Reactive block copolymers

ABSTRACT

A process for making a block copolymer compatibilizer, comprising reacting an acrylic monomer that has functional groups with one or more vinyl monomers in the presence of a free radical initiator and a stable free radical to form a reaction product that includes residual unreacted acrylic monomer, and reacting one or more vinyl monomers with the reaction product to form a second block that incorporates the residual unreacted acrylic monomer. A blend composition comprising a first thermoplastic polymer, which has functional groups, a reactive block copolymer that has functional groups in two or more blocks, and a second thermoplastic polymer that is compatible with one block of the block copolymer, where the functional groups in the first thermoplastic react with the functional groups in the block copolymer.

CROSS REFERENCE TO RELATED APPLICATION

Priority is claimed to U.S. Provisional Patent Application Ser. No.60/711,890 filed by the inventors on Aug. 26, 2005, which isincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to a process for making block copolymerscontaining a reactive functional group, such as anhydride, epoxy, amine,amide, hydroxyl or acid groups, in two or more blocks via free radicalpolymerization in the presence of a stable free radical, a compositionof matter comprising block copolymers containing a reactive monomer ormonomers in two or more blocks via free radical polymerization and useof the composition of matter as a compatibilizer in blending polymers.

2. Description of the Related Art

The blending of polymers provides a powerful route for obtainingmaterials with improved property/cost performances. Since most polymerpairs are immiscible, a compatibilization strategy is required to obtainmaximum synergy of properties. This strategy is usually cheaper and lesstime-consuming than the development of new monomers and/or newpolymerization routes, as the basis for entirely new polymericmaterials. An additional advantage of polymer blends is that a widerange of material properties is within reach by merely changing theblend composition. Compatibilization of polymer blends can be achievedusing compatibilizers, which are macromolecular species exhibitinginterfacial activities in heterogeneous polymer blends. Usually thechains of a compatibilizer have a blocky structure, with oneconstitutive block miscible with one blend component and a second blockmiscible with the other blend component. Another option forcompatibilization is the addition of a reactive polymer, miscible withone blend component and reactive towards functional groups attached tothe second blend component, which results in an “in-situ” formation ofblock or grafted copolymers. This technique has certain advantages overthe addition of pre-made block or grafted copolymers. Usually reactivepolymers can be generated by free radical copolymerization or by meltgrafting of reactive groups on to chemically inert polymer chains.Furthermore, reactive polymers only generate block or grafted copolymersat the site where they are needed, i.e. at the interface of animmiscible polymer blend.

The successful development of compatibilizers that permit composites ofpolyolefins such as polypropylene and minerals, glass and/or polarthermoplastics, having excellent physical properties was rapid. By theearly 1970's compatibilizers based on maleated polypropylene wereavailable for the manufacture of polyolefin-based composite materials.The maleic anhydride moieties of these compatibilizers is reacted withthe nucleophilic amines and hydroxyl functional groups in polyamides,polyesters and polycarbonates and with the amino silanes used to modifythe surface of glass fibers and other mineral fillers.

Attempts to apply the analogous solution to the other major hydrocarbonpolymer group, styrenics, have been without success. Maleation ofpolystyrene is random along the polystyrene chain and is not located onthe ends of the chain, as in the case for polypropylene. Similarly,copolymerization of styrene monomer and maleic anhydride yields analternating copolymer, and copolymerization of styrene with othernucleophile reactive monomers is random along the polystyrene chain.Such candidate compatibilizers contain functional groups that arereactive with the nucleophiles present in the polar thermoplastics andamine modified fillers and therefore interact with the polar phase ofthe composites (e.g., glass, minerals, and or polar thermoplasticpolymers), yielding in some cases more uniform dispersions of the onematerial in the other. However, because the architecture of thesecandidate compatibilizers is random, there are no separate domains, andtherefore, no domain that is compatible with the styrene phase of thecomposite and sufficiently long to chain entangle with the polystyrenein the composite. As a result, even with improved dispersion of onephase in the other, the required improvement in the physical propertiesof the alloy material is not achieved, and, indeed, sometimes there iseven a degradation of physical properties compared to the same alloywithout the candidate compatibilizer (Dong, C., et. al., Polymer, 1996,37, 14, 3055-3063; Chang, F., et al., Polym. Eng. Sci., 1991, 31, 21,1509-1519; Jannasch, P., et. al., J. Appl. Polym. Sci., 1995, 58,753-770).

The successful strategy with polyolefin composites and failure inpolystyrene composites was studied and reported by Fumio Ide (Ide, F.,et. al., J. Appl. Polym. Sci., 1974, 18, 4, 963-74). As mentioned inU.S. Pub. No. 2005/004310 A1, researchers recognized that the presenceof reactive functional groups like maleic anhydride were necessary incompatibilizers, but not sufficient for good compatibilization. Inaddition to this, the placement of the nucleophile reactive functionalgroups within the compatibilizer polymer architecture has been random.Compatibilizer materials that present a block copolymer structure, inwhich each one of the blocks is thermodynamically compatible with one oftwo polymeric materials to be blended, perform more effectively ascompatibilizers than their random copolymer counterparts (U.S. Pub. No.2004/0077788A1). Well-defined styrene block copolymers containingreactive groups have been prepared and applied as reactivecompatibilizers, but they usually exhibit important disadvantages, suchas: i) complex synthetic techniques, ii) the presence of unstable andcorrosive moieties and iii) the addition of an extraneous polymer withdifferent chemical and physical properties (Park, C., et. al., Polymer,2001, 42, 7465-7475; U.S. Pat. No. 6,417,274 B1; Koulouri, E. G., et.al., Macromolecules, 1999, 32, 6242-6248).

In order to obtain well defined block copolymers to be used ascompatibilizers, several approaches have been taken, and one approach isthe use of living polymerization processes. Living polymerizationprocesses, in which termination reactions are suppressed orsignificantly reduced, allow for the formation of block copolymers, asthe life of each individual chain is extended to periods comparable tothe duration of the process (minutes or hours). It is possible toproduce block copolymers with functional groups by anionicpolymerization, but this technique presents severe limitations for itsbroad practical application. On one hand, it requires conditions ofextreme purity in the monomers because humidity traces destroy thecatalyst, and for many monomers it is very difficult to control,requiring extremely low temperatures. Also, the polymerization ofmonomers having functional groups is not practical since the catalystcan be destroyed by the presence of a number of functional groups. As aresult, the industrial application of this technique is reduced to a fewmonomers, leaving out technologically-important functional monomers.

Due to limitations in the anionic polymerization process, a morepromising technique for producing block copolymers with a large varietyof monomers is that based on living or quasi-living free radicalpolymerization. This can be achieved by adding, to an otherwise standardfree radical polymerization recipe, a chemical agent that significantlyreduces the extent of irreversible termination or chain transferreactions, conferring a living or quasi-living character to thepolymerization, which is also called “controlled polymerization” or“controlled free radical polymerization.” There are several ways toobtain this behavior (Sawamoto, et. al., Chem. Rev. 2001, 101,3689-3745), but most of them are limited in an industrial practicebecause they require chemical agents that are not readilycommercially-available in the market. Among these techniques, one thatis particularly useful, and for which the required chemical agents areavailable in the market, is a quasi-living free radical polymerizationcontrolled by nitroxides (nitroxide mediated radical polymerization,NMRP), and derivatives thereof (like alcoxyamines, U.S. Pat. No.6,455,706 B2, which act as stable free radicals capping polymericgrowing radicals and uncapping them in a fast and reversible way,allowing for short periods of propagation through monomer-addition steps(U.S. Pat. No. 5,401,804; EP 0 869 137 A1; U.S. Pat. No. 6,258,911 B1;U.S. Pat. No. 6,262,206 and U.S. Pat. No. 6,255,448 B1).

Nitroxide mediated radical polymerization or NMRP has been used toprepare diblock copolymers as additives for preparing lubricating oilcompositions as reported by Visger et. al. (U.S. Pat. No. 6,531,547 B1),and recently, it has been used as a technique to obtain pure diblockcopolymers that are able to act as compatibilizers in polymer blends.U.S. Patent Application Pub. No. 2005/0004310, filed by Hong et al.,discloses the compatibilization of a styrenic polymer/polyamides orstyrenic polymer/glass, using diblocks of styrene and a styrenicreactive block. The reported technique involves the purification of thefirst synthesized block (diluting with THF, adding methanol orwater/methanol and drying) before adding the second monomer in order tohave a pure polystyrene block. A variation of this approach that hasbeeri successfully applied in polyphenylene ether-polyamide blends (U.S.Pat. No. 6,765,062 B2) is the synthesis of end-functionalized polymersusing a functional alcoxyamine (U.S. Pat. No. 6,566,468 B1; U.S. Pub.No. 2004/0049043A1). This approach requires a special controlling agentbearing epoxy functionality, which is not believed to be commerciallyavailable, and is more expensive than simple controlling agents such asTEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) or TEMPO derivatives.Another approach to the synthesis of pure block copolymers is takingadvantage of the natural alternate polymerization of certain monomerslike maleic anhydride and styrene in the presence of a nitroxide inorder to control molecular weight and polydispersity, as described inthe present assignee's U.S. Patent Application Pub. No. 2004/0077788A1,entitled Block Copolymers Containing Functional Groups, which isincorporated by reference.

Successful reactive compatibilizers described in the prior art arenonrandom block polymers, based on copolymers consisting of one reactiveblock and one nonreactive block or in special cases, only one reactivemonomer at the polymeric chain end. However, in order to obtain pureblocks, an intermediate purification step is required, such as solventevaporation, precipitation and evaporation, and the purification stepincreases the cost of the process. Only in the case where the monomersnaturally create an alternating composition, such as in the case ofstyrene and maleic anhydride, are blocks formed as a consequence ofreactivity, where a purification step is not required. Consequently,there remains a need for improvements in the field of compatibilizers.

SUMMARY OF THE INVENTION

The present invention provides a process for making a block copolymerhaving a first block with functional groups provided via an acrylicmonomer, where no purification step is used after polymerizing the firstblock so that an amount of unreacted residual monomer, which hasfunctional groups, is intentionally left in the reaction product fromthe first step. A second block is added to the first block to form theblock copolymer. The second block is preferably polymerized from atleast one vinyl monomer and the residual unreacted monomer that hasfunctional groups. Functional groups are consequently added into thesecond block, as well as into the first block, which was discovered toprovide a block copolymer that has a good performance as acompatibilizer.

In one embodiment, the present invention provides a process for making ablock copolymer, which includes the steps of reacting an acrylicmonomer, which has functional groups, and one or more vinyl monomers inthe presence of a free radical initiator and a stable free radical toform a reaction product, where the reaction product includes residualunreacted acrylic monomer, and reacting one or more vinyl monomers withthe reaction product to form a second block, where the second blockincorporates the residual unreacted acrylic monomer.

In one embodiment, the present invention provides a block copolymer thathas a composition that includes a first block, which comprises monomericunits of a functionalized acrylic monomer and monomeric units of a vinylmonomer, and a second block, which comprises monomeric units of one ormore vinyl monomers and monomeric units of the functionalized acrylicmonomer from the first block. In a preferred embodiment, the blockcopolymer is adapted for use as a compatibilizer for blends ofmaterials, particularly for blends of thermoplastic polymers.

In contrast with block copolymer compatibilizers described in the priorart, the present inventors discovered unexpectedly that impure blockcopolymers according to the present invention (where at least one typeof reactive acrylic monomer is present in the first and in the secondblock, since monomers remaining from the first block synthesis are notremoved and are thus incorporated into the second block) can efficientlywork as reactive compatibilizers of thermoplastic polymer blends. In oneembodiment, the present invention provides the following blendcomposition, which is typical of blend compositions for which theinventive copolymers work as compatibilizers.

A typical inventive blend composition comprises from about 1 to about 98wt % of a first thermoplastic polymer, which has functional groupsselected from the group consisting of amino, amide, imide, carboxyl,carbonyl, carbonate ester, anhydride, epoxy, sulfo, sulfonyl, sulfinyl,sulfhydryl, cyano and hydroxyl, from about 0.01 to about 25 wt % of ablock copolymer that includes a first block, which has monomeric unitsof a functionalized acrylic monomer and monomeric units of a vinylmonomer and a second block, which has monomeric units of one or morevinyl monomers and monomeric units of the functionalized acrylic monomerin the first block, and from about 1 to about 98 wt % of a secondthermoplastic polymer, which is miscible with or compatible with thesecond block of the block copolymer, and where the acrylic monomer hasfunctional groups that should react with the functional groups in thefirst thermoplastic polymer.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the invention can be obtained when thedetailed description of exemplary embodiments set forth below isconsidered in conjunction with the attached drawings, which aredescribed as follows.

FIG. 1 is a process schematic of a batch process according to thepresent invention.

FIG. 2 is a process schematic of a continuous process according to thepresent invention.

FIG. 3 is a photomicrograph of a blend composition according to thepresent invention.

FIGS. 4 a and 4 b are photomicrographs of a prior art blend composition.

FIG. 5 is a photomicrograph of a blend composition according to thepresent invention.

FIG. 6 is a photomicrograph of a prior art blend composition.

FIG. 7 is a photomicrograph of a prior art blend composition.

FIGS. 8 a and 8 b are photomicrographs of a blend composition accordingto the present invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The present invention provides a process, a block copolymer made by theprocess, in which the composition, microstructure and molecular weightof the copolymer are carefully controlled, and applications for theblock copolymer as a compatibilizer. The term microstructure refers to adetailed sequence or arrangement of units of each of the monomers in anaverage or typical copolymer chain. The term composition refers to theoverall average relative amount of monomers in copolymer chains, whichcan be expressed in a molar or weight basis. In particular, oneembodiment of the invention comprises block copolymers having a firstblock of a random copolymer with a total length between 1 and 720monomeric units and a second block that incorporates residual monomersleft over from the polymerizing the first block and one or moreadditional monomers, where the second block has a length between 100 and2000 monomeric units.

A block copolymer can be made according to the present invention using atwo-step process comprising: (1) reacting an acrylic monomer havingfunctional groups and one or more vinyl monomers in the presence of afree radical initiator and a stable free radical to form a reactionproduct, wherein the reaction product includes residual unreactedacrylic monomer, and (2) reacting one or more vinyl monomers with thereaction product from step one to form a second block, wherein thesecond block incorporates the residual unreacted acrylic monomer.Monomers are polymerized using a stable free radical and a traditionalfree radical initiator or an alcoxyamine, and in a second step, monomersand optionally more initiator are added. Solvents can be used optionallyin either or both steps.

The reaction product from the first step includes a first block that isa copolymer of the acrylic monomer and the one or more vinyl monomersand an amount of the acrylic monomer that was not polymerized. In thesecond step, one or more vinyl monomers copolymerize with the acrylicmonomer left over from the first step to add to the first block and formthe second block of the block copolymer. An initial portion of thesecond block may tend to have a higher proportion of the acrylic monomerbecause the acrylic monomer may become depleted before a final portionof the second block is formed by polymerization of the one or more vinylmonomers in the near absence of acrylic monomer.

The block copolymer of the present invention has a number ofapplications, one of which is as a compatibilizer for making blends ofdifferent materials, such as two different thermoplastics or of athermoplastic and a glass or clay, that are otherwise relativelyimmisicible. Such compatibilizers used in the past for blending wereoften a block copolymer having a first block compatible with a firstmaterial and a second block compatible with a second material, where thefirst and second blocks were each essentially pure. The presentinventors discovered unexpectedly that a block copolymer having arelatively impure second block, where the second block includes monomerused in the first block, performs well.

Chemical Synthesis of Block Copolymers

In a first step, an acrylic monomer that has functional groups iscopolymerized in a reactor with at least one vinyl monomer using a freeradical initiator and a stable free radical, which forms a first blockin the reactor. The reaction is conducted so as to leave an amount ofresidual unreacted acrylic monomer after the completion of the firststep so that the first block is mixed in with the residual unreactedacrylic monomer. A solvent can be used in the first step when it isdeemed necessary. In either the same reactor or in a different reactor,at least one vinyl monomer is reacted with the first block and theresidual unreacted acrylic monomer to add a second block to the firstblock to form a block copolymer having at least first and second blocks.The first block typically contains more functional groups from theacrylic monomer than the second block, but the second block has somefunctional groups because the residual unreacted acrylic monomer fromthe first step was added into the polymer chain of the second block.

The reaction product from the first step includes a copolymer of theacrylic monomer and the one or more vinyl monomers, which comprises thefirst block of the functionalized block copolymer, and a variable amountof unreacted monomers, including the acrylic monomer that was notpolymerized. The amount of functional acrylic monomer incorporated inthe first block and contained in the residual monomers can be calculatedusing commercially-available software such as POLYRED (an open-endedpackage for the computer-aided analysis and design of polymerizationsystems under development at the University of Wisconsin PolymerizationReaction Engineering Laboratory). In general, the composition of thecopolymer comprising the first block will depend on the initialcomposition, the final conversion and the reactivity ratios (for adefinition of reactivity ratios and values for a variety of monomerpairs see J. Brandrup, E. H. Immergut, E. A. Grulke. Polymer Handbook,fourth edition, John Wiley and Sons, Inc. II/181). The amount offunctional acrylic monomer in the residual monomers can beexperimentally determined by common analytical techniques such as: Gaschromatography, Nuclear magnetic resonance (NMR) or any technique thatallows the quantification of a monomer in a mixture of monomers. Ifsolvent is used during the first step, the amount of solvent should betaken into account to correct the determined weight percent (% wt.) of aparticular monomer in the remaining mixture of unreacted monomers. Ifthe technique can quantify all the species contained in the reactionproduct from the first step (NMR, for example), then it can quantify theamount of functional acrylic monomer in the residual monomers (moleculesof functional acrylic monomer*100/(total amount monomer molecules) andthe amount of functional acrylic monomer incorporated in the polymer(molecules of functional acrylic monomer in the polymer*100/(totalamount monomer molecules in the polymer).

The residual monomers from the first block contain at least 1% w/w ofthe functionalized acrylic monomer, but more preferably in the range of5-95% w/w, and most preferably in the range of 5-85% w/w. In the secondstep, one or more vinyl monomers copolymerize with the acrylic monomerand other monomers left over from the first step to add to the firstblock and form the second block of the block copolymer. The amount offunctional acrylic monomer in the second block will depend on theconcentration of the residual functional acrylic monomer in the residualmonomers from the first block, on the first block conversion and on theamount of monomers added in the second step. The composition of thesecond block at different conversions can also be calculated usingcommercially-available software such as POLYRED, including in thecalculation the three or more monomers that are involved in thepolymerization of the second block. Preferred concentration of thefunctionalized acrylic monomer in the block copolymer ranges betweenabout 0.5 and about 70 weight percent but more preferably in the rangeof 0.5 and about 50% w/w. The total amount of functional acrylic monomerincorporated in the block copolymer can be quantified using techniquessuch as NMR.

The synthesis of block copolymers by a procedure in which the firstblock is not purified or has not converted to 100% was addressed in 1994by Georges et. al. (U.S. Pat. No. 5,401,804). More recently Visger, et.al (U.S. Pat. No. 6,531,547B1) and Po, et. al (WO 2004/005361A1)disclosed the synthesis of block copolymers using a processes thatcomprises polymerizing at least one vinylaromatic monomer until acertain conversion is obtained (5-95 mole % in the case of Visger and5-99% in the case of Po) and then adding a monomer deriving frommethacrylic acid (Po) or an acrylic monomer and optionally additionalvinyl aromatic monomers (Visger). Po discusses the advantage of notisolating the first block in terms of eliminating the onerousprecipitation and recovery phase of the first polymeric block. Incontrast with the prior art, in the present invention a functionalacrylic monomer is polymerized in the first block (in contrast to avinyl aromatic monomer), in order to incorporate reactive groups (epoxy,acid, anhydride, amine, amide and hydroxyl groups) that are required indifferent applications described below (for example, reacting with afunctional thermoplastic polymer in polymeric blends). In contrast withthe prior art, in the present invention, the conversion of monomers inthe first block and the amount of initial functional acrylic monomer arecalculated in order to assure the presence of residual functionalacrylic monomer that will be incorporated in subsequent blocks, and notmerely as means of facilitating the next polymerization step, avoiding apurification step. In the present invention, we have unexpectedly foundthat the presence of reactive groups in the second block is useful forthe application of these block copolymers as compatibilizers fordifferent blends and composites. The presence of the functional acrylicmonomer in subsequent blocks has at least two advantages.

One advantage is that the acrylic monomer modifies the polarity ofsubsequent blocks in order to match the polarity of one of the polymerblend components. The advantage of using functional acrylic monomers isthat, in general, they are more polar than monomers such as vinylaromatic monomers, and the presence of a controlled amount of functionalacrylic monomers in the second and/or subsequent blocks can raise thepolarity improving their miscibility with different materials such asthermoplastic polymers.

Another advantage is that in the case of applications such as blendcompatibilizers, previous investigators had proven the superiorperformance of pure diblock copolymers over random copolymers. Thus, theneed of a purification step for the first block is a requisite to obtaingood results (Stott, P., U.S. Pub. No. 2005/004310 A1), unless themonomers used in the synthesis of the first block formed structures suchas an alternating block, eliminating the need of a purification step(Saldivar, et. al., U.S. Pub. No. 2004/0077788A1). In contrast, in thepresent work the present inventors unexpectedly found that diblockcopolymers, which were not purified after the first block wassynthesized, and which include functional reactive groups in both thefirst and the second or subsequent blocks, perform well ascompatibilizers. The present inventors believe that one of the possibleexplanations to this behavior is that the second block (miscible with anon functional thermoplastic polymer), containing reactive functionalgroups (incorporated from the unreacted monomers of the first step), isable to attach to the reactive thermoplastic polymer at differentpoints, as illustrated in Illustration 1 below, improving the interfacecontact between a non-reactive and a reactive thermoplastic polymer.(See for example, a comparison between the behavior of a diblock vs. atriblock, and the stable structure formed by a triblock in Chin-An, et.al., Macromolecules, 1997, 30, 549-560.) In the case of randomcopolymers this advantage is usually not obtained since the functionalgroups are distributed randomly along the chain, and the number ofmonomeric units of vinyl monomers miscible with the thermoplasticpolymer is probably not large enough to form entanglements with thethermoplastic monomer, and although it is strongly attached to thefunctional thermoplastic polymer, its interaction with the thermoplasticpolymer is not good enough.

Illustration 1. The compatibilizer diblock The compatibilizer triblockThe compatibilizer block copolymer of the copolymer crosses the boundarycopolymer crosses the boundary present invention crosses the boundary ofof the two thermoplastics once. of the two thermoplastics twice. the twothermoplastics more than two It “joins” both thermoplastics It “joins”both thermoplastics times, “joining” both thermoplastics by one C-C bondby two C-C bond by more than two C-C bonds Thermoplastic polymer

Functional thermoplastic polymer Pure diblock containing reactive Puretriblock copolymer Block copolymer functional acrylic monomer just incontaining reactive functional acrylic containing reactive functionalone block monomer in the first and third block acrylic monomer in bothblocks ∘ ∘ Vinyl monomer ● Functional acrylic monomer In the three casesit's considered that the number of vinyl monomeric units compatible ormiscible with the thermoplastic polymer is enough to entangle with thethermoplastic polymer (above the entanglement polymerization index)Illustration 1 is a schematic representation of the structure of a purediblock, a pure triblock and a block copolymer containing reactivefunctional acrylic monomer in both blocks according to the presentinvention.

A preferred stable free radical for use in the inventive processcontains the group .O—N<and is selected from the family of nitroxyradical compounds. Typical examples of nitroxy radical compoundsinclude, but are not limited to,

Other compounds in the family include those mentioned in the U.S. Pat.No. 4,521,429, issued to Solomon et al., WO2004014926 (A3), issued toCouturier, Jean Luc, et. al., US2003125489, issued to Nesvadba Peter,et. al., US2001039315, issued to Nesvadba Peter, et. al. In cases wherelarger amounts of methacrylic monomer are polymerized, nitroxides, suchas tert-butyl 1-diethylphosphono-2,2-dimethylpropyl nitroxide,tert-butyl 1-phenyl-2-methylpropyl nitroxide, are preferred.

Preferred free radical initiators for use in the inventive processinclude peroxide and azo compounds. Typical examples include, but arenot limited to, 2,2′-Azobis(2-Methylpropanenitrile),2,2′-Azobis(2-Methylbutanenitrile), dibenzoyl peroxide (BPO), tert-Amylperoxy-2-ethylhexanoate, tert-Butyl peroxy-2-ethylhexanoate,2,5-Bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane and tert-Butylperoxydiethylacetate.

Although the nitroxide mediated radical polymerization method isspecifically mentioned herein to prepare the compatibilizers of thepresent invention, those skilled in the art will recognize that any ofthe other well-known, so called “living”, “pseudo-living” or“controlled” radical polymerization methods can be used in the presentinvention. Such stable free radical polymerization methods include thepresence of species which reversibly terminate chains by: i) reversiblehomolytic cleavage of covalent species, ii) reversible formation ofpersistent hypervalent radicals and iii) degenerative transfer. (Moad,G.; Solomon, D., The Chemistry of Radical Polymerization. 2^(nd)edition. Elsevier, UK, 2006, chapter 9; Controlled RadicalPolymerization, Matyjaszewski, K., editor, American Chemical Society,Washington, D.C., 1997, Chapter 1; Sawamoto, et. al., Chem. Rev. 2001,101, p3691). These methods include, but are not limited to, iniferters,organosulfur iniferters, Reversible Addition-Fragmentation Transfer(RAFT) reactions, sulfur-centered radical-mediated polymerization, AtomTransfer Radical Polymerization (ATRP), reverse atom transfer radicalpolymerization (reverse-ATRP), metal complex-mediated radicalpolymerization, oxygen-centered radical-mediated polymerization,nitrogen-centered radical-mediated polymerization, iodine-transferpolymerization, telluride-mediated polymerization, stibine-mediatedpolymerization. Any one of these methods for providing a stable freeradical polymerization can be used according to the present invention.

In the present invention one of the monomers is an acrylic monomerhaving functional groups which is added during the first step. Acrylicmonomers contain vinyl groups, that is, two carbon atoms double bondedto each other, directly attached to the carbonyl carbon (C═C—CO—). Thefunctional groups contained in the acrylic monomers include, but are notlimited to, epoxy, acid, anhydride, amine, amide and hydroxyl groups.Preferred acrylic monomers that have functional groups include: glycidylmethacrylate, acrylic acid, methacrylic acid, 2-hydroxyethylmethacrylate, maleic anhydride, 2-dimethylaminoethyl methacrylate and2-diethylaminoethyl methacrylate.

In the present invention one or more vinyl monomers are added in thefirst step and in the second step of the polymerization process. A vinylmonomer is a compound that has a vinyl group C═C—. Examples of vinylmonomers are styrene, substituted styrenes, ethylene, isoprene,isobutylene, butadiene, acrylates, methacrylates, substituted acrylates,substituted methacrylates, acrylonitrile, N-phenyl maleimide,N-cyclohexyl maleimide, maleic anhydride. Preferred vinyl monomers inthe first step include styrene, substituted styrenes, acrylates,methacrylates, substituted acrylates and substituted methacrylates.Preferred vinyl monomers in the second step include styrene, substitutedstyrenes, acrylonitrile, N-aromatic substituted maleimides, N-alkylsubstituted maleimides, maleic anhydride, acrylic acid, methylmethacrylate, alkyl substituted acrylates, aryl substituted acrylates,alkyl substituted methacrylates, aryl substituted methacrylates and2-hydroxyethyl methacrylate.

In one embodiment, the functional acrylic monomer is selected from thegroup consisting of glycidyl methacrylate, maleic anhydride,2-hydroxyethyl methacrylate, acrylic acid and 2-diethylaminoethylmethacrylate and the vinyl monomer used in the first step is styrene. Inone embodiment, the vinyl monomers in the second step can be selectedfrom, but not restricted to, the group consisting of styrene, N-phenylmaleimide, methyl methacrylate and butyl methacrylate.

In a preferred embodiment, the functional acrylic monomer is glycidylmethacrylate.

In a preferred embodiment, styrene is used as the vinyl monomer in thesecond step.

In a specific embodiment, the vinyl monomer in the second step includesN-aromatic substituted maleimides or N-alkyl substituted maleimides.

In a specific embodiment, the vinyl monomer in the second step isselected from the group consisting of styrene, substituted styrenes,acrylonitrile, N-aromatic substituted maleimides, N-alkyl substitutedmaleimides, maleic anhydride, acrylic acid, methyl methacrylate, alkylsubstituted acrylates, aryl substituted acrylates, alkyl substitutedmethacrylates, aryl substituted methacrylates and 2-hydroxyethylmethacrylate.

In a specific embodiment, the acrylic monomer is selected from the groupconsisting of glycidyl methacrylate, acrylic acid, methacrylic acid,2-hydroxyethyl methacrylate, maleic anhydride, 2-dimethylaminoethylmethacrylate and 2-diethylaminoethyl methacrylate.

In a specific embodiment, the vinyl monomers of the first step areselected from a group consisting of styrene, substituted styrenes,substituted acrylates and substituted methacrylates.

In a specific embodiment, the acrylic monomer is selected from the groupconsisting of acrylic functional monomers bearing epoxy, acid,anhydride, amine, amide and hydroxyl groups.

In a specific embodiment, the one or more monomers in the second step isstyrene.

In a more specific embodiment, the acrylic monomer is glycidylmethacrylate and the vinyl monomer used in the first step is styrene.

In a more specific embodiment, the acrylic monomer is acrylic acid andthe vinyl monomer used in the first step is styrene.

In a more specific embodiment, the acrylic monomer is maleic anhydrideand the vinyl monomer used in the first step is styrene.

In a more specific embodiment, the acrylic monomer is 2-hydroxyethylmethacrylate and the vinyl monomer used in the first step is styrene.

In a more specific embodiment, the acrylic monomer is2-diethylaminoethyl methacrylate and the vinyl monomer used in the firststep is styrene.

In a more specific embodiment, the acrylic monomer is glycidylmethacrylate, the vinyl monomer used in the first step is styrene andthe vinyl monomers used in the second step are styrene andN-phenylmaleimide.

In a more specific embodiment, the acrylic monomer is glycidylmethacrylate, the vinyl monomer used in the first step is styrene andthe vinyl monomers used in the second step are styrene,N-phenylmaleimide and methyl methacrylate.

In another more specific embodiment, the acrylic monomer is glycidylmethacrylate, the vinyl monomer used in the first step is styrene andthe vinyl monomers used in the second step are styrene, methylmethacrylate and butyl acrylate.

In the present invention the proportion of the functional acrylicmonomer in step one is in the range of from about 0.1 to about 98percent by weight, more preferably in the range of from about 5 to about95 percent by weight.

In the present invention the reaction product from step 1 containsresidual unreacted monomers. The residual monomers from the first blockcontain at least 1% w/w of the functionalized acrylic monomer, but morepreferably contain in the range of 5-95% w/w, and most preferably in therange of 5-85% w/w. The weight or mass percentage of a component is theweight or mass of the component divided by the weight or mass of themixture that contains the component and is indicated by the notation %w/w or % wt or wt %.

In cases where the monomers do not react with acids, acids can be usedas promoters to reduce the reaction time. Promoters include, but are notlimited to, strong acids, mineral acids, sulfonic acids, acidic clays,organic sulfonic acids, carboxylic acids, acidic salts of any of theseacids and monoester of sulfurous and sulfuric acids.

Process Conditions

The synthesis conditions of the polymerization reaction for obtainingthe copolymers of the present invention are described next. Bulk orsolution processes can be employed. For the solution process, anysolvent that forms a solution with the initial monomers, initiator andstable free radical or alcoxyamine can be used. In the cases where asolvent is added during the second step, any solvent that forms asolution with the initial block, remaining monomers and additionalmonomers can be used. Typical solvents include aromatic or substitutedaromatic hydrocarbons, as well as aliphatic and substituted aliphatichydrocarbons. If used, the preferred solvents are substituted aromatics,more preferably toluene, xylene or ethyl benzene or polar solvents likeacetone, chloroform, ethyl acetate or water. When used, the solvent ispreferably present in amounts of about 5 to about 95% by weight on thebasis of the mixture of monomers and solvent.

With a low percentage of solvent, the solvent process is similar to abulk process, and the solvent is mainly used to control the reactionrate, to better remove the heat of reaction, to lower the viscosity andto allow for larger compositions of monomers that are non miscible inall proportions (for example styrene/maleic anhydride orstyrene/N-phenylmaleimide, or styrene/acrylamide) without having phaseseparation. A low percentage of solvent is preferably 10-30% by weightand more preferably 15-25% by weight with respect to the mixture ofmonomers and solvent. A solvent percentage of less than about 5% is ofpractically no use as the advantages of using solvent are not apparent.It may be better to switch to a bulk process rather than use a very lowpercentage of solvent.

With a high percentage of solvent, the solution process is a typicalsolution process presenting much lower viscosity, lower rate ofreaction, as well as easier temperature control and removal of heatgenerated by the polymerization reaction. A high solvent percentagepreferably ranges between about 60 and about 95 percent by weight, morepreferably between about 70 and about 90 weight % and most preferablybetween about 75 and about 88% by weight with respect to the mixture ofmonomers and solvent. A solvent percentage larger than about 95% leavestoo little polymer to be produced, and the process becomes inefficient.Solvent percentages between about 30 and about 60% can be used, but arenot recommended because they are too diluted to present the highproductivity advantage of a bulk process and too concentrated to havethe benefits given by the low viscosity of a typical solution process.

Preferred process temperatures are in the range of about 70 to about180° C., but more preferably in the range of about 90 to about 170° C.and most preferably between about 110 and about 130° C. Temperatureslower than about 70° C. do not allow the nitroxide-type radical to actas a live polymer capping-decapping moiety, as is further explainedbelow, because at these temperatures the nitroxide-type radical hindersthe living character of the polymerization. Temperatures higher thanabout 200° C. promote too many side reactions, and the living characterof the polymerization is also hindered under these conditions.

The initiator is typically used in a proportion of about 1 part ofinitiator to about 50 to about 12,000 parts in moles of monomer, morepreferably about 1 mole of initiator to about 100 to about 3,000 molesof monomer and most preferably about 1 mole of initiator to about 100 toabout 1,500 moles of monomer. Mole proportions of about 1 part ofinitiator to less than about 50 parts of monomer yield polymer of verylow molecular weight, which are usually not very good for applicationsinvolving compatibilization of polymer blends.

The aforementioned initiators have half-life times in the order of a fewminutes or less, typically less than 10 min., at the preferred processtemperatures. The amount of stable free radical (SFR) with respect toinitiator is preferably in the range of about 1 to about 1.9 moles permole of initiator, more preferably between about 1 and about 1.6 molesper mole of initiator. Ratios of SFR to initiator smaller than about 1mole of SFR per mole of initiator lead to loss of the living characterof the polymerization. However, ratios larger than about 1.9 moles ofSFR per mole of initiator can slow down the reaction too much and makethe process uneconomical. Additional amounts of initiator can also beadded in the second step of the polymerization.

After charging the ingredients, monomers, initiator and stable freeradical or an alcoxyamine instead of the initiator and nitroxide, into areactor and quickly heating to the proper temperature, most of thepolymeric chains will start early in the reaction, since the initiatorwill decompose very fast at the specified temperature. The nearlysimultaneous initiation of most of the chains will contribute tonarrowing the polydispersity. Also, soon after initiation, and havingadded only one or to a few monomeric units, each living (growing oractive) polymer chain will become dormant (deactivation) after beingcapped by the stable free radical, which will be present in a slightexcess with respect to the number of growing or living chains. Thedormant chain will remain in that state for some time until the stablefree radical is released again (activation) and the chain becomes activeor living again, and capable of adding one or more monomeric units untilit becomes again dormant. The cycle of statesliving-dormant-living-dormant repeats itself a number of times until nomore monomer is available for reaction, or the temperature is loweredbelow the minimum temperature for activation of the stable free radical,which is below around 100° C. for most of the available nitroxyradicals.

Irreversible termination reactions, such as those occurring by couplingreactions between two living chains, are hindered due to the lowereffective concentration of living polymer. The resulting process issimilar to a true living process (for example, anionic polymerization)and it is therefore considered to be quasi-living (also called“controlled”). Since all the chains grow at approximately the same rateand are initiated at about the same time, the molecular weightdistribution tends to be narrow, with relatively low polydispersity. Itis well known in the art that the degree of livingness of suchpolymerizations can be measured by the degree of linearity of thepolymer number average molecular weight growth with conversion, and bythe shifting of curves of the molecular weight distribution towardlarger values as the polymerization proceeds.

After heating from 1 to 10 hours, more typically 1-6 hours, a conversionof about 10-95%, more typically around 40-85% is reached. Up to thispoint, a first block of a pseudo living random copolymer, with orwithout some degree of alternation, has been formed. At this point, amixture of one or more vinyl monomers is added. These monomers, togetherwith the remaining monomers from the first step, will constitute asecond block. Once the solution is heated again the chains will continuegrowing, due to the dormant-living repetitive cycles, adding monomerunits from the residual (unreacted) monomer from the first step and alsofrom the monomers added in the second step, according to theirreactivity, until all the monomer is depleted or the reaction isterminated otherwise.

In the process just described, the temperature can be constant and setat one of the values mentioned in the preferred embodiments of thepresent invention or can be changed in an increasing fashion, still inthe range given in the preferred embodiments of this invention, in orderto accelerate the monomer depletion after the initial conversion stages.

Structure of the Block Copolymers

Block copolymers according to the present invention comprise a firstblock comprising monomeric units of a functionalized acrylic monomer andmonomeric units of a vinyl monomer and a second block comprisingmonomeric units of one or more vinyl monomers and monomeric units of thefunctionalized acrylic monomer in the first block.

Given the synthesis procedure described above, and the fact that thereactivity ratios determine the instantaneous composition of thecopolymer chains being added to the growing chains, each main block orportion of the copolymer will show some drift in composition, strictlymaking each one of the main portions a gradient copolymer. In this way,these blocks or portions will have some random character as well as somegradient character. What character dominates each block or portion willdepend on how different the reactivity ratios are and the additionsequence of monomers followed during the synthesis. Also, the synthesisprocedure will dictate the average composition of each of the mainblocks or portions in the final copolymer chain. In the case where thevinyl monomers added in the second step tend to alternate with theremaining monomers from the first step, the polymerization will yield atriblock, since once the monomer that tends to alternate is depleted,the other monomers will continue to homo or copolymerize.

A typical composition of the copolymers obtained is:R(I)-{(A)_(m)(B)_(n)}-{(A)_(o)(B)_(p)(C)_(q)}_(z)-I(R)

where

-   -   R is the residue of a nitroxide used to regulate the        polymerization of the compatibilizer;    -   I is the residue of a radical initiator used to initiate        polymerization or the labile alkyl group originally bonded to        oxygen of the nitroxide group contained in an alcoxyamine;    -   A is an acrylic monomer having functional groups,    -   B and C are vinyl monomers, which are either different or the        same;    -   m is an integer from 5 to 500;    -   n is an integer from 1 to 400;    -   o is an integer from 1 to 450; o is smaller than m;    -   p is an integer from 0 to 350; p is smaller than n; and    -   q is an integer from 1 to 900.

Considering the composition of these main blocks or portions of thefinal resulting copolymer formed, one possible architecture willcomprise: i) a block of mostly random copolymer A and B (withcomposition drift), ii) a mostly gradient copolymer portion or block,consisting of a terpolymer A, B and C (possibly only A and C if monomerB was depleted during the first stage), and iii) towards the end of thesecond portion or block, the chain will consist only of a block of C andpossibly A, which can be considered a block on its own. In the case thatsome monomer B remains after the first stage, the second block orportion will be a gradient copolymer gradually richer in C and less richin B.

More monomers can be included in the block copolymers. For example, if afourth monomer D is added during the first block synthesis, theresulting structure will include monomer D in the first and secondblock, in a concentration that depends on its initial concentration andreactivity. Thus the composition of this diblock could be described as:R(I)-{(A)_(m)(B)_(n)(D)_(r)}-{(A)_(o)(B)_(p)(D)_(t)(C)_(q)}-I(R) where ris an integer from 1 to 400 and t is an integer, smaller than r. Ifmonomer D is added during the second block synthesis, the resultingstructure will include D only in the second block. Thus the compositionof this diblock could be described as:R(I)-{(A)_(m)(B)_(n)}-{(A)_(o)(B)_(p)(C)_(q)(D)_(t)}-I(R), where t is aninteger from 1 to 400. In case where monomer D tends to alternate withthe remaining monomers from the first step, the polymerization willyield a triblock, since once monomer D is depleted, the other monomerswill continue to homo or copolymerize.

The functional groups contained in the acrylic monomers can be, but arenot limited to, epoxy, acid, anhydride, amine, amide and hydroxylgroups. Preferred acrylic monomers having functional groups includeglycidyl methacrylate, acrylic acid, methacrylic acid, 2-hydroxyethylmethacrylate, maleic anhydride, 2-dimethylaminoethyl methacrylate and2-diethylaminoethyl methacrylate.

Examples of vinyl monomers are styrene, substituted styrenes, ethylene,isoprene, isobutylene, butadiene, acrylates, methacrylates, substitutedacrylates, substituted methacrylates, acrylonitrile, N-phenyl maleimide,N-cyclohexyl maleimide, maleic anhydride. Preferred vinyl monomers inthe first block are styrene, substituted styrenes, acrylates,methacrylates, substituted acrylates and substituted methacrylates.

Preferred vinyl monomers in the second block are styrene, substitutedstyrenes, acrylonitrile, N-aromatic substituted maleimides, N-alkylsubstituted maleimides, maleic anhydride, acrylic acid, methylmethacrylate, alkyl substituted acrylates, aryl substituted acrylates,alkyl substituted methacrylates, aryl substituted methacrylates and2-hydroxyethyl methacrylate.

In a specific embodiment the acrylic monomer is glycidyl methacrylateand the vinyl monomer in the first and second block is styrene.

In a specific embodiment the acrylic monomer is glycidyl methacrylate,the vinyl monomer in the first block is styrene and the vinyl monomersin the second block are styrene and N-phenylmaleimide.

In a specific embodiment the acrylic monomer is glycidyl methacrylate,the vinyl monomer used in the first block is styrene and the vinylmonomers in the second block are styrene, N-phenylmaleimide and methylmethacrylate.

In a specific embodiment the acrylic monomer is glycidyl methacrylate,the vinyl monomer in the first block is styrene and the vinyl monomersin the second block are styrene, methyl methacrylate and butyl acrylate.

Preferred concentration of the residual functional acrylic monomer inthe residual monomers from the first block range about 1-95% w/w, butmore preferably in the range of from about 5 to about 85% w/w.

Preferred concentration of the functionalized acrylic monomer in theblock copolymer ranges between about 0.5 and about 70 weight percent butmore preferably in the range of from about 0.5 to about 50% w/w.

To form a specific embodiment 1, shown below, in a system of monomers, Ais glycidyl methacrylate, B is styrene and C is styrene. Glycidylmethacrylate tends to react in a random fashion with styrene forming afirst block consisting of poly(styrene-co-glycidyl methacrylate). In thesecond step, styrene will be added resulting in a gradient blockcontaining fewer glycidyl methacrylate molecules, since the remainingglycidyl methacrylate from the first block is diluted with more styreneadded in the second step, forming embodiment 1. The amount of monomericunits in the first block can be controlled with the first blockconversion, and the amount of monomeric units in the second block can becontrolled either with the amount of monomer added in the second step orwith the final conversion. The composition of each block can becontrolled by the mole percent of monomers added during the first andsecond step.

Embodiment 1

Where:I is the residue of a radical initiator used to initiate polymerizationor the labile alkyl group originally bonded to oxygen of the nitroxidegroup contained in an alcoxyamine;R is the residue of a nitroxide used to regulate the polymerization ofthe compatibilizer;m is an integer from 5 to 500;n is an integer from 1 to 400;o is an integer from 1 to 450; o is smaller than m; andp is an integer from 0 to 350.

Considering the composition of these main blocks or portions of thefinal resulting copolymer formed, one possible architecture willcomprise: i) a block of mostly random copolymer A and B (withcomposition drift), ii) an alternating copolymer consisting of aterpolymer A, B and C or an alternating copolymer of A and C or analternating copolymer of B and C, depending on the reactivities of eachmonomer, and iii) once monomer C is depeleted, the remaining monomer ormonomers will continue to homo or copolymerize forming a third block.

Another typical composition of the copolymers obtained is:R(I)-{(A)_(m)(B)_(n)}-{(A)_(o)(B)_(p)(C)_(q)}_(z-){(A)_(r)(B)_(s)}_(z)-I(R)

where

-   -   R is the residue of a nitroxide used to regulate the        polymerization of the compatibilizer;    -   I is the residue of a radical initiator used to initiate        polymerization or the labile alkyl group originally bonded to        oxygen of the nitroxide group contained in an alcoxyamine;    -   A is an acrylic monomer having functional groups;    -   B and C are different vinyl monomers;    -   m is an integer from 5 to 500;    -   n is an integer from 1 to 400;    -   o is an integer from 1 to 450; o is smaller than m;    -   p is an integer from 0 to 350; p is smaller than n;    -   q is an integer from 1 to 900;    -   r is an integer from 0 to 450; r is equal or smaller than o; and    -   s is an integer from 0 to 350; s is equal or smaller than p.

In a specific embodiment the monomers are: A=glycidyl methacrylate,B=styrene, C=N-phenyl maleimide and D=styrene. Monomers A and B arecharged in the first step, producing a random copolymer. After a 66-70%conversion is reached, monomers C and D are added. In this second block,styrene will alternate with N-phenyl maleimide also incorporating theremaining glycidyl methacrylate. Depending on the proportions ofmonomers A, B, C and D, and the conversion reached in the second block,the second block can be: i) mainly an alternating block, or ii) mainlyan alternating block and after monomer C and A are depleted, monomer B/Dcan continue forming a third block of homopolymer or iii) mainly analternating block and after monomer C is depleted, monomers B/D and Acan continue forming a third copolymer block. The structures obtained ineach case (i, ii, and iii) are shown below as Embodiments 2a, 2b and 2c.

Where in Embodiments 2a, 2b and 2c:I is the residue of a radical initiator used to initiate polymerizationof the compatibilizer or the labile alkyl group originally bonded tooxygen of the nitroxide group contained in an alcoxyamine;R is the residue of a nitroxide used to regulate the polymerization ofthe compatibilizer;m is an integer from 5 to 500;n is an integer from 1 to 400;o is an integer from 1 to 450; o is smaller than m;p is an integer from 0 to 350; p is smaller than n;q is an integer from 1 to 900;r is an integer equal or smaller than o; ands is an integer smaller than p.

The different structures shown in Embodiments 2a, 2b and 2c can beobtained by modifying the proportions of monomers and the conversions ofthe first and the second block, which makes this a very versatileprocedure for obtaining a variety of structures.

The block copolymers of the present invention use acrylic monomers as“carriers” of functional groups since one can find almost all importantfunctional groups in commercially available and relatively economicacrylic monomers. For example, the epoxy group can be introduced byusing glycidyl methacrylate, the acid group by using acrylic acid, theanhydride group by using maleic anhydride, the amine group by using2-(diethylamino)ethyl methacrylate, the amide group by using acrylamideor maleimide and the hydroxyl group by using 2-hydroxyethylmethacrylate. Another advantage is that the functional acrylic monomerthat is incorporated in the second block can raise its polarity makingit more miscible with certain thermoplastic polymers (this polarity canbe tuned by adjusting the amount of residual functional acrylic monomerand the amount of monomers added in the second step), since acrylicmonomers, in general, have higher polarities compared to other monomers,such as vinyl aromatic monomers. The presence of functional acrylicmonomers in the first block and in the remaining unreacted monomers ofthe first step, yields a mixture with a high enough polarity to directlyincorporate other highly polar monomers in the second step, such asN-phenyl maleimide and methyl methacrylate, without having to add asolvent. The commercial availability and variety of functional groupsfound in relatively inexpensive acrylic monomers and the higher polarityof these types of monomers are advantageous over the use of vinylaromatic monomers with functional groups, such as described in U.S. Pat.No. 6,531,547 B1 and in International Application Publication No. WO2004 005361 A1.

Depending on the nature of the functional acrylic monomers, the blockcopolymers can be water soluble, they can carry positive or negativecharge or charges in their functional groups or they can be neutral.Also depending on the nature of the functional acrylic monomers and thevinyl monomers, block copolymers can form amphiphilic copolymers. Inprior art processes for the production of block copolymers using livingpolymerizations, a sequence of several chemical steps is necessary: in afirst step the monomer forming the first block is homopolymerized untilit is consumed, if pure blocks are to be obtained. If the first monomeris not totally consumed, it has to be removed before the second monomeris added. In a further chemical step, a second monomer is added, and itpolymerizes, extending the living chains formed during the first stepand generating a second block. The need to remove the residual monomerbefore the charge of a second monomer represents an additional andlikely difficult step, which is avoided by the process of the presentinvention.

Triblock Copolymer

A triblock copolymer can be made according to the present inventionusing a two-step process comprising: 1) reacting an acrylic monomerhaving functional groups and one or more vinyl monomers in the presenceof a bifunctional controlling agent (see for example U.S. Pat. No.6,258,911 B1) to form a reaction product, wherein the reaction productincludes residual unreacted acrylic monomer, and 2) reacting one or morevinyl monomers with the reaction product from step one, wherein theblocks formed incorporate the residual unreacted acrylic monomer.Solvents can be used optionally in either or both steps. Radicalinitiators can be used optionally in either or both steps.

One possible structure of triblock copolymers is:R-{(A)_(o)(B)_(p)(C)_(q)}_(z)-{(A)_(m)(B)_(n)(I—I)}-{(A)_(o)(B)_(p)(C)_(q)}_(z)—R

where

-   -   R is the residue of a nitroxide or controlling agent used to        regulate the polymerization of the compatibilizer;    -   I—I is the residue of a molecule used to initiate polymerization        or the labile alkyl group originally bonded to oxygen of the        nitroxide group contained in an alcoxyamine;    -   A is an acrylic monomer having functional groups;    -   B and C are different or equal vinyl monomers;    -   m is an integer from 5 to 500;    -   n is an integer from 1 to 400;    -   o is an integer from 1 to 450; o is smaller than m;    -   p is an integer from 0 to 350; p is smaller than n; and    -   q is an integer from 1 to 900.

Depending on the different vinyl monomers added during the first andsecond step, the amount of controlling agent and initiator and theconversion of each step, a wide variety of structures can be obtained.

A procedure that can be used to obtain triblock copolymers containingfunctional acrylic monomers in two or three of their blocks consists ofcontinuing the polymerization after a certain conversion of the secondblock polymerization has been reached. The third block can be optionallysynthesized after the diblock is purified, by dissolving it in one ormore vinyl monomers. Optionally, more initiator can be added, andoptionally, solvent can be used.

Batch Process

The present invention also provides a chemical batch process to performthe polymerization reaction, which is performed in two process stages asfollows:

-   -   a) A first stage involving adding all the reactants comprising        the first block of the block copolymer into a reactor with        agitation and heating to reach conversions of about 14 to about        95%, and    -   b) A second stage involving adding additional monomers to the        product of the first reactor and continuing the reaction in a        different reactor vessel or vessels without agitation, up to        conversions of about 90 to about 100%.

The reactor used in the first step is a well agitated reactor suppliedwith a helical-type or anchor-type impeller. This reactor must also havesome means of exchanging heat with the exterior by a device such as ajacket or a coil for heating and cooling. After reaching conversions inthe range of 14-95%, more preferably 50-90%, the viscosity of thereaction mixture will increase and stirring will be difficult, so thereaction product is transferred to a mixing tank where additionalmonomers are added prior to a final transfer to a reactor where thereaction is completed. This second reactor is preferably a vesselwithout an agitation device for easier cleaning, such as a slab-shapedor cylinder-shaped reactor or reactors. This second reactor should alsobe provided with some way of exchanging heat such as an external jacket,immersion in a thermal fluid, or any other similar means. After reachinghigh conversion, which can be aided by increasing the temperature as thereaction time proceeds, the polymer is removed from the second stagereactor or reactors and ground into smaller pieces in a mechanical mill.Final conversions of less than about 90% are not convenient as muchresidual monomer would be left, affecting the properties and handling ofthe final product.

FIG. 1

With reference to FIG. 1, a batch process 10 according to the presentinvention is shown schematically. A solution of nitroxy radical, anacrylic monomer having functional groups and one or more vinyl monomersare added to a tank 12, which is connected through a line 14 to a pump16. The mixture in tank 12 is pumped through line 18 into a reactor 20.A catalyst or initiator is placed in tank 22, which is connected by aline 24 to a pump 26. Pump 26 pumps the catalyst or initiator through aline 28 into reactor 20. Reactor 20 is a continuous stirred tank reactorand is connected by a line 30 to a pump 32. After the first block of theblock copolymer is formed in reactor 20, the copolymer and unreactedmonomer are pumped by pump 32 through a line 34 to mixing tank 36. Asolution of one or more vinyl monomers is added to tank 38. The contentsof tank 38 flow through a line 40 to a pump 42, which pumps the contentsthrough a line 44 to the mixing tank 36. These monomers will become partof the second block of the block copolymer. The agitated mixing tank 36is connected by a line 46 to a pump 48. After the additional monomersare thoroughly mixed the solution is pumped by pump 48 through a line 50to a set of slab molds 52. Conversion in reactor 20 is typically in therange of from about 14 to about 95%. Slab molds 52 provide a secondreactor vessel, which is without agitation, and heat is shown added andremoved schematically through a line 54 to a thermal bath 56. Variousmethods can be used to remove heat, such as by a jacketed reactor or bycirculation of reactants through a heat exchanger. The solid polymercoming from the slab molds is then ground using a granulator 58,typically a rotary knife granulator or a hammer mill. The ground productis then ready for packaging or can optionally be dried in an oven toremove any residual monomer left over from the final polymerizationstep.

The acrylic monomer having functional groups, one or more vinylmonomers, nitroxy radical and initiator can be charged directly toreactor 20. By adjusting or manipulating the ratio of initiator tomonomer and/or the ratio of the nitroxy radical to initiator, themolecular weight of the copolymer can be controlled. Examples areprovided below, which provide further insight on the impact of theseratios on molecular weight. In this manner, the microstructure of theblock copolymer can be controlled and thus made as desired. Reactor 20has been shown as a continuous stirred tank reactor, but other types ofreactors can be used, preferably providing some type of agitation.Reactor 52 has been shown as a slab mold reactor, but other types ofreactors, such as a tubular reactor, can be used, preferably providing aquiescent reaction zone.

Continuous Process

The present invention further provides a bulk or solution continuousprocess to perform the polymerization reaction, comprising two processsteps in series as follows:

-   -   a) A first step involving heating the reaction mixture in a        continuous stirred tank reactor with exit conversions between 14        and 95% weight, and    -   b) A second step involving heating in a kneader-mixer reactor in        which the exit conversion is between about 60 and about 100%

The reactor used in the first step is similar to the one just describedfor the batch process; that is, a well agitated reactor supplied with ahelical-type or anchor-type impeller and provided with some means ofexchanging heat with the exterior. The preferred conversions are betweenabout 10-95%, more preferably 50-90% at the temperatures preferred inthis invention. Conversions smaller than about 10% will make the use ofthe first reactor inefficient and conversions larger than about 95% willmake the process difficult to control due to the high viscosity of thereaction mixture and may broaden too much the molecular weightdistribution of the polymer, rendering the material heterogeneous. Thesecond reactor is a kneader-mixer, as shown for example in U.S. Pat.Nos. 4,824,257; 5,121,992; and 7,045,581 and in Publication No.WO2006034875, which provides further conversion without broadening toomuch the molecular weight distribution and allows for easier polymertransport and heat removal. Kneader-mixers exhibit narrower residencetime distributions than their agitated tank counterparts, and it is wellknown in the art that, for living or quasi-living polymerizationreactions, the molecular weight distribution of the polymer isdetermined by the residence time distribution of the reactor. Also,since the conversion in the second reactor is higher than in the firstone, the viscosity will also be very high and in these conditionskneader-mixers provide an ideal way to transport the polymer and removethe heat of reaction, since these reactors generally have a betterarea-to-volume ratio for heat exchange. Conversions smaller than about60% at the exit result in an inefficient use of the second reactor andleave too much unreacted monomer. After the second reactor, the processmust provide some means of removing the unreacted monomer, such asdevolatilizer equipment or an extruder with venting. Unreacted monomercan be recovered and recycled to the process.

FIG. 2

With reference to FIG. 2, a continuous process 60 is shown schematicallyaccording to the present invention. A solution of nitroxy radical, anacrylic monomer having functional groups and one or more vinyl monomersare added to tank 62. The contents of tank 62 flow through a line 64 toa pump 66, which pumps the contents through a line 68 to reactor 70,which can be a continuous stirred tank reactor. A catalyst or initiatoris placed in tank 72, and the contents of tank 72 flows through a line74 into a pump 76, which pumps the catalyst or initiator through a line78 into reactor 70. The first block of the block copolymer is formed inreactor 70, where conversion is preferably in the range of from about 14to about 95%. The copolymer and unreacted monomer flow out of reactor 70through a line 80 into a pump 82, which pumps the fluid through a line84 into a tubular-type reactor 86, which can be a kneader-mixer. Asolution of one or more vinyl monomers is added to tank 88. The contentsof tank 88 flow through a line 90 to a pump 92, which pumps the contentsthrough a line 94 to the reactor 86. A conversion ranging from about 60to about 100% is achieved in reactor 86, and the block copolymer andunreacted monomer flow out of reactor 86 through a line 96 into adevolatilizer 98. Monomer is recovered from devolatilizer 98 through aline 100, which flows into a condenser 102. A condensate is formed andflows through a line 104 into a condensate tank 106. Block copolymer iswithdrawn from devolatilizer 98 through a line 108 into a pump 110 fortransfer.

Blend Compatibilization

Another embodiment of this invention is the use of the reactive blockcopolymers as a compatibilizer in compositions, comprising:

-   (a) 1-98 wt % of a thermoplastic having functional groups selected    from the group comprising: amino, amide, imide, carboxyl, carbonyl,    carbonate ester, anhydride, epoxy, sulfo, sulfonyl, sulfinyl,    sulfhydryl, cyano and hydroxyl;-   (b) 0.01-25 wt % of a block copolymer comprising:    -   i) a first block comprising monomeric units of a functionalized        acrylic monomer and monomeric units of a vinyl monomer; and    -   ii) a second block comprising monomeric units of one or more        vinyl monomers and monomeric units of the functionalized acrylic        monomer in the first block, where the block copolymer contains        functional groups capable of reacting with the chemical moieties        of thermoplastics including the thermoplastics having the        functional groups in component (a), preferably having Mn of        5,000 to 350,000; and-   (c) 1-98 wt % of a thermoplastic polymer miscible or compatible with    the second block of the block copolymer described in component    (b). 32. Preferred block copolymer Mn in thousands is 8.5-350,    5-200, 10-150 or 20-120.

The invention thus provides many applications in which the inventiveblock copolymer is used as a compatibilizer, which provides acomposition of matter for a compatibilized blend as well as a method ofuse for the compatibilizer.

Polymers miscible or compatible with the first block of theaforementioned block copolymer include those which may be described ashydrogenated or partially hydrogenated homopolymers, and random,tapered, or block polymers (copolymers, including terpolymers,tetrapolymers, etc.) of conjugated dienes and/or monovinyl aromaticcompounds. The conjugated dienes include isoprene, butadiene,2,3-dimethylbutadiene and/or mixtures thereof, such as isoprene andbutadiene. The monovinyl aromatic compounds include any of the followingand mixtures thereof: monovinyl monoaromatic compounds, such as styreneor alkylated styrenes substituted at the alpha-carbon atoms of thestyrene, such as alpha-methylstyrene, or at ring carbons, such as o-,m-, p-methylstyrene, ethylstyrene, propylstyrene, isopropylstyrene,butylstyrene, isobutylstyrene, tert-butylstyrene (e.g.,p-tertbutylstyrene). Also included are vinylxylenes, methylethylstyrenes, and ethylvinylstyrenes. Specific examples include randompolymers of butadiene and/or isoprene and polymers of isoprene and/orbutadiene and styrene and also estero-specific polymers such assyndiotactic polystyrene. Typical block copolymers includepolystyrene-polyisoprene, polystyrene-polybutadiene,polystyrene-polybutadiene-polystyrene, polystyrene-ethylenebutylene-polystyrene, polyvinyl cyclohexane-hydrogenated polyisoprene,and polyvinyl cyclohexane-hydrogenated polybutadiene. Tapered polymersinclude those of the previous monomers prepared by methods known in theart. Other non-styrenic polymers miscible or compatible with the secondblock of the copolymer include, but are not limited to, polyphenyleneether (PPE), polyvinyl methyl ether and tetramethyl polycarbonate,methyl methacrylate, alkyl substitued acrylates, alkyl substituedmethacrylates and their copolymers with styrene. It also comprisespolyolefins, where the term polyolefin is defined as a polymer themajority of whose monomers are olefins and may be polyethylene,polypropylene or co-polymers of ethylene and either propylene or vinylacetate. It also comprises engineering thermoplastic such as: aliphaticand aromatic polycarbonates (such as bisphenol A polycarbonate),polyesters (such as poly(butylene terephthalate) and poly(ethyleneterephthalate)), polyamides, polyacetal, polyphenylene ether or mixturesthereof. All these engineering thermoplastics are prepared according towell known commercial processes. Reference to such processes can befound in technical publications such as Encyclopedia of Polymer Scienceand Engineering, John Wiley and Sons., 1988, under the respectiveengineering thermoplastic polymer topic heading.

Thermoplastic Polymers that Have Functional Groups

Preferred thermoplastic polymers having functional groups are selectedfrom the group consisting of: aliphatic and aromatic polycarbonates(such as bisphenol A polycarbonate), polyesters (such as poly(butyleneterephthalate) and poly(ethylene terephthalate)), polyamides,polyacetal, polyphenylene ether, polyolefins having epoxy, anhydride oracid functionalities, polysulfones, polurethanes and mixtures thereof.All these thermoplastics are prepared according to well-known commercialprocesses. Reference to such processes can be found in technicalpublications such as Encyclopedia of Polymer Science and Engineering,John Wiley and Sons., 1988, under the respective thermoplastic polymertopic heading. Specific details on polycondensation engineeringthermoplastics follow.

The polyphenylene ethers and polyamides of the present invention are asdescribed in U.S. Pat. No. 5,290,863, which is incorporated herein byreference. The polyphenylene ethers comprise a plurality of structuralunits having the formula:

In each of said units, each independent Q1 is independently halogen,primary or secondary lower alkyl (i.e. alkyl containing up to 7 carbonatoms), phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy, orhalohydrocarbonoxy wherein at least two carbon atoms separate thehalogen and oxygen atoms; and each Q2 is independently hydrogen,halogen, primary or secondary lower alkyl, phenyl, haloalkyl,hydrocarbonoxy or halohydrocarbonoxy as defined for Q1.

Examples of suitable primary or lower alkyl groups are methyl, ethyl,n-propyl, n-butyl, isobutyl, n-amyl, isoamyl, 2-methylbutyl, n-hexyl,2,3-dimethylbutyl, 2-, 3- or 4-methylpentyl and the corresponding heptylgroups. Examples of secondary lower alkyl are isopropyl and sec-butyl.

Preferably, any alkyl radicals are straight chain rather than branched.Most often, each Q1 is alkyl or phenyl, especially C1-4 alkyl, and eachQ2 is hydrogen. Suitable polyphenylene ethers are disclosed in a largenumber of patents.

The polyphenylene ethers are typically prepared by the oxidativecoupling of at least one corresponding monohydroxyaromatic compound.Particularly useful and readily available monohydroxyaromatic compoundsare 2,6-xylenol, wherein each Q1 is methyl and each Q2 is hydrogen andwherein the resultant polymer is characterized as apoly(2,6-dimethyl-1,4-phenylene ether), and 2,3,6-trimethylphenol,wherein each Q1 and one Q2 are methyl and the other Q2 is hydrogen.

Both homopolymer and copolymer polyphenylene ethers are included.Suitable homopolymers are those containing, for example,2,6-dimethyl-1,4-phenylene ether units. Suitable copolymers includerandom copolymers containing such units in combination with, forexample, 2,3,6-trimethyl-1,4-phenylene ether units. Many suitable randomcopolymers, as well as homopolymers, are disclosed in the patentliterature.

Also included are polyphenylene ethers containing moieties which modifyproperties such as molecular weight, melt viscosity and/or impactstrength. Such polymers are described in the patent literature and maybe prepared by grafting onto the polyphenylene ether in known mannersuch vinyl monomers as acrylonitrile and vinyl aromatic compounds (e.g.styrene), or such polymers as polystyrenes or elastomers. The producttypically contains both grafted and ungrafted moieties. Other suitablepolymers are the coupled polyphenylene ethers in which the couplingagent is reacted in known manner with the hydroxy groups of twopolyphenylene ether chains to produce a higher molecular weight polymercontaining the reaction product of the hydroxy groups and the couplingagent. Illustrative coupling agents are low molecular weightpolycarbonates quinones, heterocycles and formals.

The polyphenylene ether generally has a number average molecular weightwithin the range of about 3,000 and a weight average molecular weightwithin the range of about 20,000, as determined by gel permeationchromatography. Its intrinsic viscosity is most often in the range ofabout 0.15-0.6 dl/g, as measured in chloroform at 25° C.

The polyphenylene ethers which may be employed for the purposes of thisinvention include those which comprise molecules having at least one ofthe end groups of the formulae

wherein Q₁ and Q₂ are as previously defined; each R₁ is independentlyhydrogen or alkyl, with the proviso that the total number of carbonatoms in both R₁ radicals is 6 or less; and each R₂ is independentlyhydrogen or a C₁₋₆ primary alkyl radical. Preferably, each R₁ ishydrogen and each R₂ is alkyl, especially methyl or n-butyl.

Polymers containing the aminoalkyl-substituted end groups of formula(II) may be obtained by incorporating an appropriate primary orsecondary monoamine as one of the constituents of the oxidative couplingreaction mixture, especially when a copper- or manganese-containingcatalyst is used. Such amines, especially the dialkylamines andpreferably di-n-butylamine and dimethylamine, frequently becomechemically bound to the polyphenylene ether, most often by replacing oneof the α-hydrogen atoms on one or more Q1 radicals. The principal siteof reaction is the Q1 radical adjacent to the hydroxy group on theterminal unit of the polymer chain. During further processing and/orblending, the aminoalkyl-substituted end groups may undergo variousreactions, probably involving a quinone methide-type intermediate of theformula

with numerous beneficial effects often including an increase in impactstrength and compatibilization with other blend components, as pointedout in references cited in U.S. Pat. No. 5,290,863.

It will be apparent to those skilled in the art from the foregoing thatthe polyphenylene ethers contemplated for use in the present inventioninclude all those presently known, irrespective of variations instructural units or ancillary chemical features.

Polyamides included in the present invention are those prepared by thepolymerization of a monoamino-monocarboxylic acid or a lactam thereofhaving at least 2 carbon atoms between the amino and carboxylic acidgroup, of substantially equimolar proportions of a diamine whichcontains at least 2 carbon atoms between the amino groups and adicarboxylic acid, or of a monoaminocarboxylic acid or a lactam thereofas defined above together with substantially equimolar proportions of adiamine and a dicarboxylic acid. The term “substantially equimolar”proportions include both strictly equimolar proportions and slightdepartures there from which are involved in conventional techniques forstabilizing the viscosity of the resultant polyamides. The dicarboxylicacid may be used in the form of a functional derivative thereof, forexample, an ester or acid chloride.

Examples of the aforementioned monoamino-monocarboxylic acids or lactamsthereof which are useful in preparing the polyamides include thosecompounds containing from 2 to 16 carbon atoms between the amino andcarboxylic acid groups, said carbon atoms forming a ring containing theCO(NH) group in the case of a lactam. As particular examples ofaminocarboxylic acids and lactams there may be mentioned -aminocaproicacid, butyrolactam, pivalolactam, -caprolactam, capryllactam,enantholactam, undecanolactam, dodecanolactam and 3- and 4-aminobenzoicacids.

Diamines suitable for use in the preparation of the polyamides includethe straight chain and branched chain alkyl, aryl and alkaryl diamines.Illustrative diamines are trimethylenediamine, tetramethylenediamine,pentamethylenediamine, octamethylenediamine, hexamethylenediamine (whichis often preferred), trimethylhexamethylenediamine, m-phenylenediamineand m-xylylenediamine.

The dicarboxylic acids may be represented by the formulaHOOC—B—COOH  (V)where B is a divalent aliphatic or aromatic group containing at least 2carbon atoms. Examples of aliphatic acids are sebacic acid,octadecanedioic acid, suberic acid, glutaric acid, pimelic acid andadipic acid.

Both crystalline and amorphous polyamides may be employed, with thecrystalline species often being preferred by reason of their solventresistance. Typical examples of the polyamides or nylons, as these areoften called, include, for example, polyamide-6 (polycaprolactam), 6,6(polyhexamethylene adipamide), 11, 12, 4, 6, 6, 10 and 6, 12 as well aspolyamides from terephthalic acid and/or isophthalic acid andtrimethylhexamethylenediamine; from adipic acid and m-xylylenediamines;from adipic acid, azelaic acid and 2,2-bis(p-aminophenyl)propane or2,2-bis-(p-aminocyclohexyl)propane and from terephthalic acid and4,4′-diaminodicyclohexylmethane. Mixtures and/or copolymers of two ormore of the foregoing polyamides or prepolymers thereof, respectively,are also within the scope of the present invention. Preferred polyamidesare polyamide-6, 4, 6, 6, 6, 6, 9, 6, 10, 6, 12, 11 and 12, mostpreferably polyamide-6,6. Commercially available thermoplasticpolyamides may be advantageously used in the practice of this invention,with linear crystalline polyamides having a melting point between 165and 230° C. being preferred.

Polyesters which may be employed as a component in compositions of theinvention are, in general, relatively high in molecular weight and maybe branched or linear polymers. These include polyesters such aspolyethylene terephthalate (PET), polybutylene terephthalate (PBT),polycyclohexane-bis-methylene terephthalate (PCT) and thermoplasticelastomeric, or combinations of these thermoplastic elastomericpolyesters with other above polyesters such as PBT. Polyesters suitablefor compositions of the present invention include, in general, linearsaturated condensation products of diols and dicarboxylic acids, orreactive derivatives thereof. Preferably, they are polymeric glycolesters of terephthalic acid and isophthalic acid. These polymers areavailable commercially or can be prepared by known techniques, such asby the alcoholysis of esters of the phthalic acid with a glycol andsubsequent polymerization, by heating glycols with the free acids orwith halide derivatives thereof, and similar processes. Such polymersand methods for their preparation are described further in referencescited in U.S. Pat. No. 5,290,863, and elsewhere.

Preferred polyesters are of the family comprising high molecular weight,polymeric glycol terephthalates or isophthalates having repeating unitsof the formula

where n is a whole number from two to ten, and more usually from two tofour, and mixtures of such esters, including copolyesters ofterephthalic and isophthalic acids of up to 30 mol percent isophthalicunits.

Especially preferred polyesters are poly(ethylene terephthalate) andpoly(1,4-butylene terephthalate).

Especially favored when high melt strength is important are branchedhigh melt viscosity poly(1,4-butylene terephthalate) resins whichinclude small amounts, for example, up to 5 mol percent based on theterephthalate units, of a branching component containing at least threeester forming groups. The branching component can be one which providesbranching in the acid unit portion of the polyester, or in the glycolunit portion, or it can be a hybrid. Illustrative of such branchingcomponents are tri- or tetracarboxylic acids, such as trimesic acid,pyromellitic acid, and lower alkyl esters thereof, and the like, orpreferably, tetrols, such as pentaerythritol, triols, such astrimethylolpropane, or dihydroxy carboxylic acids andhydroxydicarboxylic acids and derivatives, such as dimethylhydroxyterephthalate, and the like. The addition of a polyepoxide, suchas triglycidyl isocyanurate, which is known to increase the viscosity ofthe polyester phase through branching can aid in improving the physicalproperties of the present blends.

The branched poly(1,4-butylene terephthalate) resins and theirpreparation are described in U.S. Pat. No. 3,953,404.

Illustratively, the high molecular weight polyesters useful in thepractice of this invention have an intrinsic viscosity of at least about0.2 deciliters per gram, and more usually from about 0.4 to 1.5deciliters per gram as measured in solution in ortho-chlorophenol or a60/40 phenol/tetrachloroethane mixture at 25° to 30° C.

The linear polyesters include thermoplastic poly(alkylenedicarboxylates) and alicyclic analogs thereof. They typically comprisestructural units of the formula:

where R8 is a saturated divalent aliphatic or alicyclic hydrocarbonradical containing about 2 to 10 and usually about 2 to 8 carbon atomsand A2 is a divalent aromatic radical containing about 6 to 20 carbonatoms. They are ordinarily prepared by the reaction of at least one diolsuch as ethylene glycol, 1,4-butanediol or 1,4-cyclohexanedimethanolwith at least one aromatic dicarboxylic acid such as isophthalic orterephthalic acid, or lower alkyl ester thereof. The polyalkyleneterephthalates, particularly polyethylene and polybutylene terephthalateand especially the latter, are preferred. Such polyesters are known inthe art as illustrated by references cited in U.S. Pat. No. 5,290,863.

The linear polyesters generally have number average molecular weights inthe range of about 20,000 to 70,000, as determined by intrinsicviscosity at 30° C. in a mixture of 60% (by weight) phenol and 40%1,1,2,2-tetrachloroethane. When resistance to heat distortion is animportant factor, the polyester molecular weight should be relativelyhigh, typically above about 40,000.

The polycarbonates suitable to be used in the present compositionsinclude aliphatic and aromatic polycarbonates. Starting materials foraliphatic polycarbonates are diols and carbonates, eg, diethyl ofdiphenyl carbonate which are obtained by phosgenation of hydroxycompounds or 1,3-dioxolan-2-ones formed from CO2 and oxiranes. Aliphaticpolycarbonates may also be prepared from 1,3-dioxan-2-ones obtained bythermal depolymerization of the corresponding polycarbonates.

Current methods for the preparation of aliphatic polycarbonates includetransesterification of diols with lower dialkyl carbonates, dioxolanonesor diphenyl carbonate in the presence of catalyst such as alkali metal,tin and titanium compounds. Ring-opening polymerization of six-memberedcyclic carbonates (1,3-dioxan-2-ones), in the presence of bicycliccarbonates which act as crosslinking agents, leads to hard, toughthermosets. Crosslinked polycarbonates with outstanding properties arealso obtained by free radical polymerization of diethylene glycolbis(allylcarbonate). Based on ethylene glycol carbonate, other phosgeneroutes have been found, starting with CO2 with urea or a dialkylcarbonate as an intermediate, or from CO. Other routes involves thecationic or free radical, ring-opening polymerization of cyclic orthoesters of carbonic acid. These reactions give polyether polycarbonates.

The molecular weights of linear aliphatic polycarbonates areprocess-dependent and are between 500 and 5000. Polycarbonates withmolecular weights up to about 30,000 are obtained bytransesterification, whereas those with a molecular weight greater than50,000 are prepared by polymerization of carbonates possessingsix-membered rings.

Among the preferred polycarbonates are the aromatic polycarbonatehomopolymers. The structural units in such homopolymers generally havethe formula

wherein A₃ is an aromatic radical. Suitable A₃ radicals includem-phenylene, p-phenylene, 4,4′-biphenylene, 2,2-bis(4-phenylene)propane,2,2-bis(3,5-dimethyl-4-phenylene)propane and similar radicals such asthose which correspond to the dihydroxyaromatic compounds disclosed byname or formula, generically or specifically, in U.S. Pat. No.4,217,438. Also included are radicals containing non-hydrocarbonmoieties. These may be substituents such as chloro, nitro, alkoxy andthe like, and also linking radicals such as thio, sulfoxy, sulfone,ester, amide, ether and carbonyl. Most often, however, all A₃ radicalsare hydrocarbon radicals.

The A3 radicals preferably have the formula-A₄-Y(A5(  (IX)wherein each of A4 and A5 is a single-ring divalent aromatic radical andY is a bridging radical in which one or two atoms separate A4 from A5.The free valence bonds in formula IX are usually in the meta- orpara-positions of A4 and A5 in relation to Y. Such A3 values may beconsidered as being derived from bisphenols of the formula HO (A4 (Y(A5(OH. Frequent reference to bisphenols will be made hereinafter, butit should be understood that A3 values derived from suitable compoundsother than bisphenols may be employed as appropriate.

In formula IX, the A4 and A5 values may be unsubstituted phenylene orsubstituted derivatives thereof, illustrative substituents being one ormore alkyl, alkenyl (e.g., crosslinkable-graftable moieties such asvinyl and allyl), halo (especially chloro and/or bromo), nitro, alkoxyand the like. Unsubstituted phenylene radicals are preferred. Both A4and A5 are preferably p-phenylene, although both may be o- orm-phenylene, or one may be o-phenylene or m-phenylene and the otherp-phenylene.

The bridging radical, Y, is one in which one or two atoms, preferablyone, separate A4 from A5. It is most often a hydrocarbon radical, andparticularly a saturated radical such as methylene, cyclohexylmethylene,2-[2,2,1]-bicycloheptylmethylene, ethylene, 2,2-propylene,1,1-(2,2-dimethylpropylene), 1,1-cyclohexylene, 1,1-cyclopentadecylene,1,1-cyclododecylene or 2,2-adamantylene, especially a gemalkyleneradical. Also included, however, are unsaturated radicals and radicalswhich are entirely or partially composed of atoms other than carbon andhydrogen. Examples of such radicals are 2,2-dichloroethylidene,carbonyl, thio, oxy, and sulfone. For reasons of availability andparticular suitability for the purposes of this invention, the preferredradical of formula IX is the 2,2-bis(4-phenylene)propane radical, whichis derived from bisphenol-A and in which Y is isopropylidene and A4 andA5 are each p-phenylene.

Various methods of preparing polycarbonate homopolymers are known. Theyinclude interfacial and other methods in which phosgene is reacted withbisphenols, transesterification methods in which bisphenols are reactedwith diaryl carbonates, and methods involving conversion of cyclicpolycarbonate oligomers to linear polycarbonates. The latter method isdisclosed in U.S. Pat. Nos. 4,605,731 and 4,644,053.

A preferred polyhydric phenol is a dihydric phenol such as bisphenol A.Suitable polycarbonate resins for the practice of the present inventionmay be any commercial polycarbonate resin. The weight average molecularweight of suitable polycarbonate resins (as determined by gel permeationchromatography relative to polystyrene) may range from about 20,000 toabout 500,000, preferably from about 40,000 to about 400,000. However,compositions in which polycarbonates have a molecular weight in therange of about 80,000 often have favorable properties.

It is also possible in the polymer mixture according to the invention touse a mixture of different polycarbonates as mentioned hereinbefore asan aromatic polycarbonate.

Use of Block Copolymers as a Compatibilizer

Generally a minimum of about 0.5 wt % of reactive block copolymer of theinvention and preferably a range of from about 1 to about 7 will besufficient to observe compatibilization effects on the engineeringthermoplastic blend compositions in which used, such as improvements onmechanical properties. The block copolymer can also be used in amountshigher than the minimum but limited to a range so that it willpositively affect the blend characteristics without substantiallydegrading other sought characteristics. Thus, typical blends willcomprise the following: (a) thermoplastic having functional groups, 98-1wt % (b) thermoplastic polymer miscible or compatible with the secondblock of the block copolymer, 1-98 wt %; and (c) reactive blockcopolymer, 1-20 wt %. Preferred blends of this invention comprise fromabout 40 to about 90 wt % thermoplastic having functional groups, 10-60wt % thermoplastic miscible or compatible with the second block of theblock copolymer and about 2 to about 5 wt % of the reactive blockcopolymer. This range of compositions will usually yield materials withimproved impact properties and mechanical strength.

Generally, the blend compositions of the invention can be prepared bymixing the thermoplastic having functional groups, the thermoplasticmiscible/compatible with one of the blocks of the copolymer and thereactive block copolymer of the invention, in any order and subjectingthe mixture to temperatures sufficient to melt the mixture, for example,180° C. and up. Such mixing and heating can be accomplished usingconventional polymer processing equipment known in the art, such asbatch mixers, single or multiple screw extruders, continuous kneaders,etc. Furthermore, the compatibilized compositions of the presentinvention may contain various additives, for example, stabilizers, flameretardants, anti-oxidants, fillers, processing aids and pigments innormal and conventional amounts, dependent upon the desired end-use. Asexamples of the fillers, there may be mentioned, e.g., metal oxides suchas iron and nickel oxide, nonmetals such as carbon fiber, silicates(e.g. mica, aluminum silicate (clay)), titanium dioxide, glass flakes,glass beads, glass fibers, polymer fibers, etc. If used, theconventional additives and fillers are mechanically blended and thecompositions of the invention are then molded in known methods.

Additional Applications for the Block Copolymer as a Compatibilizer

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the thermoplastic polymer miscible orcompatible with the second block of the block copolymer is polystyrene.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the thermoplastic polymer miscible orcompatible with the second block of the block copolymer is high-impactpolystyrene.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the thermoplastic polymer miscible orcompatible with the second block of the block copolymer is high-impactpolystyrene, and in order to prepare the composition the functionalizedblock copolymer is melt blended first with a polycarbonate resin thathas been previously hydrolyzed to increase the number of availablefunctional groups. The product of this extrusion step is dried and thenmelt processed with more polycarbonate and high-impact polystyrene toprepare the final composition.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the thermoplastic polymer miscible orcompatible with the second block of the block copolymer is a copolymerof styrene, acrylonitrile and butadiene (ABS).

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the thermoplastic polymer miscible orcompatible with the second block of the block copolymer is a copolymerof styrene, acrylonitrile and n-butyl acrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the thermoplastic polymer miscible orcompatible with the second block of the block copolymer is a copolymerof styrene, acrylonitrile, butadiene and n-butyl acrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the thermoplastic polymer miscible orcompatible with the second block of the block copolymer is apolyphenylene ether.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the thermoplastic polymer miscible orcompatible with the second block of the block copolymer is a mixture ofhigh-impact polystyrene and polyphenylene ether.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the thermoplastic polymer miscible orcompatible with the second block of the block copolymer is ahydrogenated block copolymer of styrene and a diene monomer.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the reactive block copolymer comprisesglycidyl methacrylate as the functionalized acrylic monomer and styreneas the vinyl monomer in the first and second block.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the reactive block copolymer comprisesglycidyl methacrylate as the functionalized acrylic monomer and styreneas the vinyl monomer in the first block. The vinyl monomers in secondblock are styrene and N-phenylmaleimide.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the reactive block copolymer comprisesglycidyl methacrylate as the functionalized acrylic monomer and styreneas the vinyl monomer in the first block. The vinyl monomers in secondblock are styrene, N-phenylmaleimide and methyl methacrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is polycarbonate and the reactive block copolymer comprisesglycidyl methacrylate as the functionalized acrylic monomer and styreneas the vinyl monomer in the first block. The vinyl monomers in secondblock are styrene, methyl methacrylate and butyl acrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the thermoplasticpolymer miscible or compatible with the second block of the blockcopolymer is a block copolymer of styrene and a diene monomer.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the thermoplasticpolymer miscible or compatible with the second block of the blockcopolymer is a hydrogenated block copolymer of styrene and a dienemonomer.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the thermoplasticpolymer miscible or compatible with the second block of the blockcopolymer is a styrene acrylic copolymer.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the thermoplasticpolymer miscible or compatible with the second block of the blockcopolymer is polystyrene.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the thermoplasticpolymer miscible or compatible with the second block of the blockcopolymer is high-impact polystyrene.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the thermoplasticpolymer miscible or compatible with the second block of the blockcopolymer is a copolymer of styrene, acrylonitrile and butadiene.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the thermoplasticpolymer miscible or compatible with the second block of the blockcopolymer is a copolymer of styrene, acrylonitrile and n-butyl acrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the thermoplasticpolymer miscible or compatible with the second block of the blockcopolymer is a copolymer of styrene, acrylonitrile, butadiene andn-butyl acrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the reactive blockcopolymer comprises glycidyl methacrylate as the functionalized acrylicmonomer and styrene as the vinyl monomer in the first and second block.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the reactive blockcopolymer comprises glycidyl methacrylate as the functionalized acrylicmonomer and styrene as the vinyl monomer in the first block. The vinylmonomers in second block are styrene and N-phenylmaleimide.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the reactive blockcopolymer comprises glycidyl methacrylate as the functionalized acrylicmonomer and styrene as the vinyl monomer in the first block. The vinylmonomers in second block are styrene, N-phenylmaleimide and methylmethacrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polybutylene terephtalate,polyethylene terephtalate and mixtures thereof and the reactive blockcopolymer comprises glycidyl methacrylate as the functionalized acrylicmonomer and styrene as the vinyl monomer in the first block. The vinylmonomers in second block are styrene, methyl methacrylate and butylacrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polypentamethylenecarboxamide, polyhexamethylene adipamide and mixtures thereof and thethermoplastic polymer miscible or compatible with the second block ofthe block copolymer is polystyrene.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polypentamethylenecarboxamide, polyhexamethylene adipamide and mixtures thereof and thethermoplastic polymer miscible or compatible with the second block ofthe block copolymer is high-impact polystyrene.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polypentamethylenecarboxamide, polyhexamethylene adipamide and mixtures thereof and thethermoplastic polymer miscible or compatible with the second block ofthe block copolymer is a copolymer of styrene, acrylonitrile andbutadiene.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polypentamethylenecarboxamide, polyhexamethylene adipamide and mixtures thereof and thethermoplastic polymer miscible or compatible with the second block ofthe block copolymer is a copolymer of styrene, acrylonitrile and n-butylacrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polypentamethylenecarboxamide, polyhexamethylene adipamide and mixtures thereof and thethermoplastic polymer miscible or compatible with the second block ofthe block copolymer is a copolymer of styrene, acrylonitrile, butadieneand n-butyl acrylate.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polypentamethylenecarboxamide, polyhexamethylene adipamide and mixtures thereof and thethermoplastic polymer miscible or compatible with the second block ofthe block copolymer is a polyphenylene ether.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polypentamethylenecarboxamide, polyhexamethylene adipamide and mixtures thereof and thethermoplastic polymer miscible or compatible with the second block ofthe block copolymer is a mixture of high-impact polystyrene andpolyphenylene ether.

In a specific embodiment the thermoplastic polymer having functionalgroups is selected from a group consisting of polypentamethylenecarboxamide, polyhexamethylene adipamide and mixtures thereof and thethermoplastic polymer miscible or compatible with the second block ofthe block copolymer is a hydrogenated block copolymer of styrene and adiene monomer.

Blend Compositions

Generally a minimum of about 0.5 wt. % of reactive block copolymer ofthe invention and preferably a range of from about 1 to about 7 wt. %will be sufficient to observe compatibilization effects on thethermoplastic blend compositions in which used, such as improvements onmechanical properties. The block copolymer can also be used in amountshigher than the minimum but limited to a range so that it willpositively affect the blend characteristics without substantiallydegrading other sought characteristics. Thus typical blends willcomprise the following: (a) thermoplastic polymer having functionalgroups, 98-1 wt % (b) thermoplastic polymer miscible or compatible withthe second block of the block copolymer, 1-98 wt %; and (c) reactiveblock copolymer, 1-20 wt %. Preferred blends of this invention comprisefrom about 40 to about 90 wt % thermoplastic polymers having functionalgroups, 10-60 wt % thermoplastic polymers miscible or compatible withpolystyrene and about 2 to about 5 wt % of the reactive block copolymer.This range of compositions will usually yield materials with improvedimpact properties and mechanical strength.

Generally, the blend compositions of the invention can be prepared bymixing the thermoplastic polymer having functional groups, thethermoplastic miscible/compatible with the second block of the blockcopolymer and the reactive block copolymer of the invention, in anyorder and subjecting the mixture to temperatures sufficient to melt themixture, for example, 180° C. and up. Such mixing and heating can beaccomplished using conventional polymer processing equipment known inthe art, such as batch mixers, single or multiple screw extruders,continuous kneaders, etc. Furthermore the compatibilized compositions ofthe present invention may contain various additives, for example,stabilizers, flame retardants, anti-oxidants, fillers, processing aidsand pigments in normal and conventional amounts, dependent upon thedesired end-use. As examples of the fillers, there may be mentioned,e.g., metal <oxides such as iron and nickel oxide, nonmetals such ascarbon fiber, silicates (e.g. mica, aluminum silicate (clay)), titaniumdioxide, glass flakes, glass beads, glass fibers, polymer fibers, etc.If used, the conventional additives and fillers are mechanically blendedand the compositions of the invention are then molded in known methods.

Tie Layer

The functional block copolymers can also be used as compatibilizers forthermoplastic polymers as a tie layer material for adhesively bondingplastic film layers one to another to form a laminate structure thereof.The usual process for using tie layers involves extruding two plasticlayers and a tie layer, wherein the tie layer is located in between thetwo plastic layers.

Use with Clays

A mixture of the functional block copolymers and clay can be used toincorporate and effectively disperse clays into thermoplastic polymers.Thermoplastic polymers include those which may be described ashydrogenated or partially hydrogenated homopolymers, and random,tapered, or block polymers (copolymers, including terpolymers,tetrapolymers, etc.) of conjugated dienes and/or monovinyl aromaticcompounds. The conjugated dienes include isoprene, butadiene,2,3-dimethylbutadiene and/or mixtures thereof, such as isoprene andbutadiene. The monovinyl aromatic compounds include any of the followingand mixtures thereof: monovinyl monoaromatic compounds, such as styreneor alkylated styrenes substituted at the alpha-carbon atoms of thestyrene, such as alpha-methylstyrene, or at ring carbons, such as o-,m-, p-methylstyrene, ethylstyrene, propylstyrene, isopropylstyrene,butylstyrene, isobutylstyrene, tert-butylstyrene (e.g.,p-tertbutylstyrene). Also included are vinylxylenes, methylethylstyrenes, and ethylvinylstyrenes. Specific examples include randompolymers of butadiene and/or isoprene and polymers of isoprene and/orbutadiene and styrene and also estero-specific polymers such assyndiotactic polystyrene. Typical block copolymers includepolystyrene-polyisoprene, polystyrene-polybutadiene,polystyrene-polybutadiene-polystyrene, polystyrene-ethylenebutylene-polystyrene, polyvinyl cyclohexane-hydrogenated polyisoprene,and polyvinyl cyclohexane-hydrogenated polybutadiene. Tapered polymersinclude those of the previous monomers prepared by methods known in theart. Other non-styrenic polymers miscible or compatible with the secondblock of the copolymer include, but are not limited to, polyphenyleneether (PPE), polyvinyl methyl ether and tetramethyl polycarbonate,methyl methacrylate, alkyl substituted acrylates, alkyl substitutedmethacrylates and their copolymers with styrene. It also comprisespolyolefins, where the term polyolefin is defined as a polymer themajority of whose monomers are olefins and may be polyethylene,polypropylene or co-polymers of ethylene and either propylene or vinylacetate. It also comprises engineering thermoplastic such as: aliphaticand aromatic polycarbonates (such as bisphenol A polycarbonate),polyesters (such as poly(butylene terephthalate) and poly(ethyleneterephthalate)), polyamides, polyacetal, polyphenylene ether or mixturesthereof. All these engineering thermoplastics are prepared according towell known commercial processes. Reference to such processes can befound in technical publications such as Encyclopedia of Polymer Scienceand Engineering, John Wiley and Sons., 1988, under the respectiveengineering thermoplastic polymer topic heading.

A mixture of the functional block copolymers and clay can be used toincorporate and effectively disperse clays into functional polymers.Functional polymers include but are not restricted to aliphatic andaromatic polycarbonates (such as bisphenol A polycarbonate), polyesters(such as poly(butylene terephthalate) and poly(ethylene terephthalate)),polyamides, polyacetal, polyphenylene ether, polyolefins having epoxy,anhydride or acid functionalities, polysulfones, polurethanes andmixtures thereof.

A mixture of the functional block copolymers, clay and a functionalizedpolyolefin can be used to incorporate and effectively disperse claysinto nonfunctional polyolefins and improve their mechanical properties.

EXAMPLES

The following examples illustrate a number of aspects of the presentinvention. A wide variety of properties can be obtained in differentblends by merely changing the molecular weight of the block of thecompatibilizer, the amount of reactive monomers and the conversion ofthe first block. The following examples illustrate the invention in moredetail, but they should not to be construed as limiting the presentinvention to the particular examples provided. The scope of theinvention is properly determined by the claims that are ultimately underconsideration.

Preparation of Diblock Copolymers

Reagents: Glycidyl methacrylate from Dow Quimica Mexicana, S. A. de C.V.; BPO from Akzo Nobel; 4-hydroxy tempo from CIBA; N-Phenylmaleimide,Methyl methacrylate, Butyl methacrylate and Butyl acrylate were acquiredfrom Sigma-Aldrich.4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl(4-hydroxy-TEMPO) fromCIBA. These reagents were used as received. Styrene from Quimir waseither used as received (examples 1, 7-9, 14-17) or washed with a NaOHsolution in order to remove the inhibitor and dried with anhydroussodium sulfate.

Examples 2-6, 8, 10-14. General procedure (see table 1 for the amount ofreagents in each example). Styrene (St), glycidyl methacrylate (GMA),nitroxide and initiator (benzoyl peroxide, BPO) were placed in adouble-jacket glass reactor and oxygen was removed with nitrogenbubbling for 3 minutes. Oil preheated to 131° C. was circulated throughthe outside jacket, and the mixture was stirred at 145 rpm. After thedesired conversion was reached, heating was suspended and additionalstyrene and optional monomers (see table 2) were added to the reactorwith stirring. After 3 min. of stirring, the reaction was eithercontinued in the glass reactor until 10-20% more conversion was reachedor directly poured into a second reactor. Nitrogen was bubbled through,and the reactor was immersed in an oil bath, which was previously heatedto 125-130° C., for 18-24 hours to reach the desired conversion.

Examples 1, 7, 9. Styrene (St), glycidyl methacrylate (GMA), nitroxideand initiator (benzoyl peroxide, BPO) were added to a 20 literdouble-jacket stainless steel reactor, and oxygen was removed bypressurizing the reactor with nitrogen (to 6 Kg/cm²) and releasing thepressure three times. Preheated oil was circulated through the outsidejacket until a temperature of 127-129° C. was reached, and stirring wasstarted (60-80 rpm). After the desired conversion was achieved, heatingwas suspended and additional styrene and optional monomers (see table 2)were added to the reactor with stirring. After 1-3 min. of stirring, thereaction product was directly poured into a slab mold reactor. Nitrogenwas bubbled through the reaction product, and oil was circulated throughthe slab mold reactor double jacket in order to maintain an internaltemperature of 127-129° C. Heating was continued until a desiredconversion was reached. The product was released from the slab moldreactor and ground to obtain a diblock copolymer in the form ofgranules. TABLE 1 Diblock copolymers. First step composition FIRST STEPCon- Example St GMA GMA Nitroxide BPO version number (mmol) (mmol) (%mol)^(a) (mmol) (mmol) (%) 1 179.86 35.88 16.6 0.56 0.43 70.00 2 179.8835.72 16.5 0.56 0.43 70.00 3 214.32 8.91 4.0 0.62 0.48 85.20 4 293.7158.86 16.3 4.31 3.32 89.58 5 200.78 4.15 2.0 0.86 0.66 80.76 6 530.5847.28 8.1 2.48 1.91 85.00 7 265.90 52.78 16.5 0.83 0.64 82.90 8 266.2452.86 16.5 0.83 0.64 70.00 9 163.99 36.43 18.1 0.72 0.55 70.00 10 190.2027.94 12.7 0.70 0.54 78.18 11 211.25 41.97 16.5 0.66 0.51 76.07 12205.03 40.74 16.5 0.64 0.49 76.07 13 474.19 94.10 16.5 1.50 1.15 66.4014 460.76 91.48 16.5 1.44 1.11 70.00^(a)Considering the initial GMA to St ratioNOTE:table 1 shows amounts calculated for the synthesis of 100 g of thediblock, while actual amounts ware scaled up or down, depending on thesize of the reactors used for each case.

TABLE 2 Diblock copolymers. Second step composition SECOND STEP ButylButyl N-phenyl TOTAL Example Acrylate Methacrylate maleimide GMA numberSt (mmol) (mmol) (mmol) (mmol) Conversion (% mol)^(b) 1 729.52 0.00 0.000.00 99 3.8 2 730.57 0.00 0.00 0.00 99 3.8 3 731.68 0.00 0.00 0.00 990.9 4 572.32 0.00 0.00 0.00 99 6.3 5 750.95 0.00 0.00 0.00 99 0.4 6357.11 0.00 0.00 0.00 99 5.0 7 619.55 0.00 0.00 0.00 99 5.6 8 620.380.00 0.00 0.00 99 5.6 9 745.24 0.00 0.00 0.00 97 3.8 10 547.99 148.430.00 0.00 97 3.1 11 421.99 217.38 0.00 0.00 98 4.7 12 409.55 0.00 210.890.00 97 4.7 13 292.73 0.00 0.00 36.09 92 10.5 14 284.62 0.00 0.00 52.6492 10.3^(b)Considering the total GMA to monomers (1^(st) and second step) ratioNOTE:table 2 shows amounts calculated for the synthesis of 100 g of thediblock, while actual amounts ware scaled up or down, depending on thesize of the reactors used for each case.

Molecular weight distributions relative to polystyrene were determinedthrough GPC (ASTM D3536-91) using a Waters 410, RI detector, THF eluent,1.0 mL/min, at 40° C.; Styragel linear columns HR 4 and HR 3. Resultsare shown in table 3. TABLE 3 Properties of diblock copolymers. Diblockcopolymer example FIRST STEP TOTAL number Mn Mw PDI Mn Mw PDI 1 2021222546 1.12 92618 142527 1.54 2 24068 29870 1.24 64771 109887 1.70 327682 30585 1.10 92060 138132 1.50 4 7826 8857 1.13 16994 20353 1.20 515269 16837 1.10 50648 76101 1.50 6 15965 17994 1.13 25329 30624 1.21 727526 32698 1.19 49768 74509 1.50 8 32331 38528 1.19 65338 96507 1.48 924144 27555 1.14 67697 105233 1.55 10 23490 30595 1.30 70528 153445 2.1811 20813 25741 1.24 61006 125348 2.05 12 20813 25741 1.24 50622 916061.81 13 27569 34447 1.25 45396 74289 1.64 14 32331 38528 1.19 3527366288 1.88

Residual Glycidyl methacrylate (GMA). In order to determine the amountof residual GMA, the reaction mixture of example 2 (first step, after70% conversion was achieved), was analyzed using gas chromatography andthe amount of GMA was determined using a calibration curve of GMA at aknown concentration.

Table 4 shows calibration curve data used to determine GMA content: Thestandards contain a variable amount of GMA and a fixed amount of tolueneas an internal standard, both dissolved in THF. The chromatogram isintegrated and the relative areas are calculated (area of GMApeak/toluene area), a linear regression is used to correlate therelative peak area with GMA concentration (relative areas=0.4192*(GMAconcentration)+0.1138; R2=0.9972). A sample of 100 mg of the reactionmixture of example 2 (first step, after 70% conversion) was dissolved inTHF adding the same amount of toluene as an internal standard as theused in the standards. TABLE 4 Gas chromatography calibration curve dataused to determine the % w/w of GMA. GMA standards concentration Peakarea (relative to (mg/mL) the internal standard) 0 0 1.0424 0.6026865.212 2.59247 10.424 4.40227 15.636 6.273665 20.848 9.029951 26.0611.10497

The mixture of example 2, first step, shows a chromatograph with arelative peak area of 2.203, which corresponds (using the linearregression equation) to a concentration of 4.984 mg/mL. Taking intoaccount the amount of sample, this corresponds to 4.34% w/w GMA. Sincethis sample has 70% conversion, only 30% of the sample containsmonomers, and the concentration of GMA in the monomers then equals14.47% w/w (4.34 g GMA*100 g reaction mixture/30 g remaining monomermixture).

Synthesis of reference materials. In order to compare the performance ofdiblocks prepared in examples 1-14, three random copolymers wereprepared. General procedure (see table 5 for the amount of reagents ineach example). Styrene (St), glycidyl methacrylate (GMA), nitroxide andinitiator (benzoyl peroxide, BPO) were placed in a reactor, nitrogen wasbubbled through the mixture, and the reactor was immersed in an oilbath, which was previously heated to 125-130° C., for 20-24 hours toreach the desired conversion. TABLE 5 Synthesis of random copolymers.Composition analogous to example of N-phenyl Example table 1 St GMAmaleimide Nitroxide BPO Conversion GMA^(a) number number: (mmol) (mmol)(mmol) (mmol) (mmol) (%) (% mol) 15 14 745.38 91.48 52.64 1.44 1.1199.00 10.3 16 8 886.63 52.85 0.00 0.83 0.64 99.00 5.6 17 2 910.47 35.710.00 0.56 0.43 99.00 3.8^(a)Considering the total GMA to monomersratioNOTE:table 5 shows amounts calculated for the synthesis of 100 g of thediblock, while actual amounts ware scaled up or down, depending on thesize of the reactors used for each case.

The amount of monomeric units in each block can be controlled with thefirst block conversion, the total conversion and the amount of initiatorand controlling agent. The composition of each block can be controlledby the mole percent of monomers added during the first and second step.This can be better understood by looking at examples 1 to 11, wheredifferent total amounts of glycidyl methacrylate (example 4 has 6.3% molof GMA whereas example 5 has 0.4% mol) and different molecular weightsin both blocks (example 4 has a number average molecular weight (Mn) inthe first block of 7826, whereas example 8 has an Mn of 32331; example 1has a total Mn of 92618, whereas example 4 has a total Mn of 16994),depending on the initial composition of monomers, nitroxide andinitiator, the amount of styrene added in the second step, the firstblock conversion and the total conversion. The total amount offunctional acrylic monomer (GMA, in this case) can be controlled by theinitial amount of GMA added, the first block conversion and the amountof monomers added in the second step. For example, examples 2, 7 and 11have the same percent of GMA added in the first step (16.5% mol), butsince the amount of styrene added in the second step is different, theyhave different total amounts of GMA. In examples containing GMA andstyrene in the first step, since the reactivities of both monomers aresimilar, the initial mole percent of GMA added in the first step issimilar (but lower) to the mole percent incorporated in the first block.For example 2, the amount of residual GMA in the residual monomers wasquantified using gas chromatography (see description below table 3),obtaining 14.47% w/w, compared to the initial weight percent that is21.33% w/w.

Another system, in which a reactive group is contained in both blocks,is the one consisting of glycidyl methacrylate and styrene in the firststep, and N-phenyl maleimide and styrene in the second step (examples 13and 14). In these examples, since N-phenyl maleimide tends to alternate,the copolymer will consist of a triblock, where the second blockcontains the N-phenyl maleimide and the third block will consist mainlyof polystyrene.

Polymer Blends

Compatibilization of Polystyrene Acrylic Copolymer and PET Blends.

Examples 18-24. Raw materials: commercial random Poly(styrene-co-butylacrylate) (66 mol percent Styrene) and bottle grade PET (I.V. 0.75-0.9dL/g, measured in 60/40 phenol/dichlorobenzene at 25° C.).

Examples 18-24. Blending procedure.

Blends were prepared in a 90/10 weight ratio of PET pellet and theacrylic copolymer, according to table 6. For examples 51-56, thecompatibilizer was added during processing. Samples were analyzed usinga 100× magnification in an optical microscope for large particles andwhen particles were not observable at 100×, the morphology of the blendswas determined using a Carl Zeiss EM910 120 kV transmission electronmicroscope after microtoming at room temperature. Sections were stainedwith vapors of RuO₄. TABLE 6 Composition of Polystyrene acryliccopolymer/PET blends PET/Poly (styrene-co- butyl Diblock Blend. Diblockacrylate)/ Poly(styrene- co- Example copolymer diblock co-butyl polymernumber from table 1 copolymer PET (g) acrylate) (g) (g) 18 1 90 10 551.4 5.7 2.9 19 7 90 10 5 51.4 5.7 2.9 20 9 90 10 5 51.4 5.7 2.9 21 1090 10 5 51.4 5.7 2.9 22 11 90 10 5 51.4 5.7 2.9 23 12 90 10 5 51.4 5.72.9 24 none 90 10 0 54.0 6.0 0.0

TABLE 7 Microscopical analysis of blends 18-24. Blend. Particle Examplesize (μm) number Maximum Average 18 3.55 1.01 19 1.36 0.44 20 2.32 0.3321 3.70 1.21 22 36.35 3.02 23 23.75 3.15 24 10.76 0.44

In experiments 18-24 the performance of different block copolymers isevaluated in terms of the reduction of particle size in polymer blends.Table 7 shows that most of the block copolymers effectively reduce themaximum particle size (with the exception of examples 22 and 23, whosebad performance can be attributed to mixing rheological problems causedby the low Tg of the copolymers that contain butyl acrylate ormethacrylate). The performance of the block copolymers depends on avariety of variables such as the number of functional groups in eachblock, the molecular weight of each block and the composition(polarity). In the present invention these variables can be easilyadjusted in order to obtain a variety of compatibilizers with differentcomposition and molecular weights that can be tested in order todetermine correlations between structure/composition and performance.

With reference to FIGS. 3, 4 a and 4 b, the TEM photographs of examples20 and 24 show how the Poly(styrene-co-butyl acrylate (dark particles)is distributed in the PET matrix. In the case of example 24, thephotographs shown in FIGS. 4 a and 4 b show a blend withoutcompatibilizer consisting of a population of small particles (of lessthan 0.44 micrometers, μm) and a population of very large particles(around 10 micrometers). In the case of example 20, shown in FIG. 3, theaddition of only 5% of a compatibilizer dramatically improves thePoly(styrene-co-butyl acrylate dispersion, yielding a more homogeneousdistribution, with an average particle size of 0.33 μm and a maximumparticle size of 2.32 μm.

Compatibilization of PET and Poly(styrene-co-methyl methacrylate)Blends.

Examples 25-34. Raw materials: Amorphous PET (Eastman plastic, EASTARcopolyester 6763 natural) and Poly(styrene-co-methyl methacrylate) (CET115 from Resirene). PET was previously dried at a reduced pressure for 4hours at 65° C.

Examples 25-34. Blending, general procedure: All components werephysically mixed by dry blending in the proportions indicated in thefollowing table (table 8), so as to produce 60 g of the mixture. Themixture was then mixed using a Haake Mixer at 60 rpm at 150° C. for 5minutes after constant torque was reached. Samples were analyzed using a100× magnification in an optical microscope for large particles and whenparticles were not observable at 100×, the morphology of the blends wasdetermined using a Carl Zeiss EM910 120 kV transmission electronmicroscope after microtoming at 0° C. Sections were stained with vaporsof RuO₄. TABLE 8 PET/Poly(styrene-co-methyl methacrylate) blendscomposition PET/Poly(styrene-co- Poly(styrene- Blend. Diblock methylco-methyl Diblock Example copolymer methacrylate)/diblock PETmethacrylate) copolymer number from table 1 copolymer (g) (g) (g) 25 180 20 3 46.6 11.7 1.7 26 3 80 20 3 46.6 11.7 1.7 27 4 80 20 3 46.6 11.71.7 28 5 80 20 3 46.6 11.7 1.7 29 6 80 20 3 46.6 11.7 1.7 30 6 80 20 0.547.8 11.9 0.3 31 6 80 20 5 45.7 11.4 2.9 32 7 80 20 3 46.6 11.7 1.7 33 980 20 3 46.6 11.7 1.7 34 NONE 80 20 0 48.0 12.0 0.0

TABLE 9 Microscopical analysis of blends 25-34 Blend. Example Particlesize (nm) number Minimum Maximum Average 25 224 1268 530 26 113 800 40827 60 807 354 28 611 1845 1010 29 133 706 347 30 95 1265 462 31 91 2133292 32 111 1070 464 33 326 1277 640 34 732 6168 1632

Examples 25-34 show the compatibilization of PET and aPoly(styrene-co-methyl methacrylate). In these examples the threestatistical measurements of particle size considered (minimum, maximumand average) are effectively reduced by using different diblockcopolymers (see table 9). Since blend 34, without a compatibilizer,contains large particles of poly(styrene-co-methyl methacrylate), thisblend could be observed using an optical microscope. As can be seen inFIG. 6, the photomicrograph for blend 34 shows poly(styrene-co-methylmethacrylate) dispersed in PET, with average particle sizes of 1632 nm.In contrast, the TEM photograph of example 29, shown in FIG. 5, showshow a compatibilized blend has considerably smaller average particlesizes of 347 nm, and that even the largest particle (706 nm) is smallerthan the minimum particle size obtained without a compatibilizer.

Compatibilization of Polyethylene Terephtalate and SEBS Blends.

Examples 35-40. Raw materials: recycled bottle grade PET (I.V. 0.8 dL/g,measured in 60/40 phenol/dichlorobenzene at 25° C.) dried for 2 h at130° C. before use; SEBS CH-6170 and CH-6110 from Dynasol.

Examples 35-40. Blending, general procedure: All components werephysically mixed by dry blending in the proportions indicated in thefollowing table (table 10) so as to produce 2 Kg of the mixture. Themixture was extruded using a twin screw extruder ZSK-30 from Coperionand a profile temperature of: 248-270° C. The samples were cut intopellets and dried. The materials were injected at a temperature of260-275° C. and a mould temperature of 65-70° C. The injected materialswere evaluated according to ASTM D638 and ASTM D256 as shown in table 11TABLE 10 Composition of PET/SEBS blends. Diblock Blend. copolymer PET/Example from table 1 SEBS^(a)/ Diblock number or table 5 Diblock PET (g)SEBS (g) (g) 35 16 75 20 5 1500.0 400.0 100.0 36 8 75 20 5 1500.0 400.0100.0 37 16 80 15 5 1600.0 300.0 100.0 38 8 80 15 5 1600.0 300.0 100.039 none 70 30 0 1400.0 600.0 0.0 40 none 70 30 0 1400.0 600.0 0.0^(a)In all cases SEBS CH6170 was used with the only exception of examplenumber 40, where SEBS CH6110 was used.

TABLE 11 Mechanical properties of examples 35-40 Tensile Tensile NotchedStrength, Tensile Strength, Tensile Izod Impact Yield Strain, BreakStrain, (0.125 in) Blend. (Kpsi) Yield (%) (Kpsi) Break (%) lb-ft/inExample ASTM ASTM ASTM ASTM ASTM number D638 D638 D638 D638 D256 35 4.584.78 — 0.00 11.27 36 4.65 4.81 — 0.00 13.71 37 5.17 4.79 2.57 134.421.63 38 5.28 4.90 — 0.00 11.35 39 ND ND ND ND 1.34 40 ND ND ND ND 0.89ND: Not determined

The compatibilization of PET and SEBS shown in examples 35-40 isachieved using different reactive block copolymers. In these examples arandom copolymer with the same composition (examples 35 and 37,containing polymer 16) is also included for comparison purposes. Themechanical properties of these blends show that the reactive diblockcopolymer 8 has superior properties compared with the random copolymerin analogous compositions (Table 11, blend 35 vs 36 and blend 37 vs 38).When the notched Izod impact of these blends is compared, superiorimpacts are obtained with the block copolymer 8, compared with therandom copolymer 16 (blend 35 vs 36 and blend 37 vs 38). The blendwithout compatibilizer was evaluated using even more SEBS (30% SEBS) toemphasize that even with high amounts of impact modifier, the blend hasvery poor impact properties.

Examples 35-40 show how the block copolymers of the present inventioncan effectively modify the impact properties of recycled PET by makingit compatible with SEBS.

Compatibilization of Polycarbonate and Acrylonitrile-butadiene-styrene(PC/ABS) Blends

Examples 41-53. Raw materials: Polycarbonate Lexan 121 was acquired fromGeneral Electric and Terluran GP35 (ABS) from BASF. Materials were driedfor 4 hours before use.

Examples 41-53. Blending, general procedure. All components werephysically mixed by dry blending in the proportions indicated in thefollowing table (table 12) so as to produce 2 Kg of the mixture. Themixture was extruded using a twin screw extruder ZSK-30 from Coperionand a profile temperature of: 248-270° C. The samples were cut intopellets and dried. The materials were injected at a temperature of265-275° C. and a mould temperature of 45° C. The injected materialswere evaluated according to ASTM D638 and ASTM D256 as shown in table13.

Example 48 was analyzed using a 100× magnification in an opticalmicroscope. As shown in FIG. 7, a photomicrograph of blend 48 shows a cocontinuous morphology. In contrast, for the compatibilized blend ofexample 53, shown in FIGS. 8 a and 8 b, observed particles at 100× weresmaller and had to be further analyzed with TEM (Jeol 200 KV), aftermicrotoming at 0° C. and staining with vapors of RuO₄(ABS is shown indark in the photograph). The photomicrograph of example 53, FIGS. 8 aand 8 b, shows a dramatic improvement in particle size of ABS dispersedin PET, compared to the blend without compatibilizer. The averageparticle size is of 0.867 micrometers. TABLE 12 PC/ABS blendscomposition Diblock Blend. copolymer PC/ Example from table 1 ABS/number or table 5 Diblock PC (g) ABS (g) Diblock (g) 41 none 50 50 01000.0 1000.0 0.0 42 13 50 50 5 952.4 952.4 95.2 43 14 50 50 5 952.4952.4 95.2 44 none 60 40 0 1200.0 800.0 0.0 45 15 60 40 3 1165.0 776.758.3 46 14 50 50 3 970.9 970.9 58.3 47 14 60 40 3 1165.0 776.7 58.3 48none 70 30 0 1400.0 600.0 0.0 49 14 70 30 5 1333.3 571.4 95.2 50 13 6040 5 1142.9 761.9 95.2 51 14 60 40 5 1142.9 761.9 95.2 52 13 70 30 51333.3 571.4 95.2 53 14 70 30 3 1359.2 582.5 58.3

TABLE 13 Mechanical properties of examples 41-53 Tensile NotchedStrength, Tensile Tensile Tensile Izod Impact Yield Strain, Strain,Modulus (0.125 in) Blend. (Kpsi) Yield (%) Break (%) (Kpsi) lb-ft/inExample ASTM ASTM ASTM ASTM ASTM number D638 D638 D638 D638 D256 41 6.752.99 2.82 334.13 0.29 42 7.02 4.31 18.05 358.72 0.81 43 7.14 4.62 16.38348.26 1.01 44 7.46 4.52 6.78 343.35 1.13 45 7.46 4.79 19.49 333.00 1.5346 7.06 4.34 20.92 346.84 3.04 47 7.66 4.95 21.68 346.05 4.27 48 7.965.03 12.88 338.14 4.44 49 8.16 5.23 17.78 349.01 4.87 50 7.61 5.00 21.00340.34 5.12 51 7.59 4.91 19.09 350.98 5.44 52 8.13 5.17 16.77 349.735.47 53 8.12 5.28 22.25 344.56 6.27

Table 13 shows the mechanical properties and notched Izod Impact ofPC/ABS blends using: i) Different proportions of PC to ABS, ii)different compatibilizers iii) a random copolymer with analogousmolecular weight and composition than the evaluated block copolymer. Thebetter performance of the block copolymer (Table 13, example 47 usingdiblock of example 14) compared to the random copolymer (example 45using random block copolymer of example 15) is revealed in all themechanical properties of the blend and is more dramatically observed inthe Notched Izod impact value. In fact, the impact obtained with therandom copolymer (1.53 lb-ft/in, example 45) is similar to the oneobtained without a compatibilizer (1.13 lb-ft/in, example 44) and islower than the one obtained with the diblock copolymer (4.27 lb-ft/in,example 47). Better impact properties are obtained for blends containingmore polycarbonate, obtaining 6.24 lb-ft/in for the compatibilized blendwith 3% wt compatibilizer against 4.44 lb-ft/in of the blend withoutcompatibilizer.

Examples 41-53 show how the block copolymers of the present inventioncan improve impact properties of polycarbonate by making it morecompatible with ABS.

Compatibilization of Polycarbonate and High-Impact Polystyrene Blends

Examples 54-56. Raw materials: Polycarbonate (PC) Lexan 121 and 141 wasacquired from General Electric; High-impact polystyrene (HIPS)containing 40 rubber was obtained as a special grade from Resirene; Flowadditive Joncryl ADP 1200 from Johnson Polymers and the antioxidantU-626 from Crompton. Polymers were dried before use.

Examples 54-56. Blending, general procedure. All components werephysically mixed by dry blending in the proportions indicated in thefollowing table (table 14). The mixture was extruded using a twin screwextruder (ZSK-30 from Coperion) and a profile temperature of: 255-270°C. The samples were cut into pellets and dried. The materials wereinjected at a temperature of 265-275° C. into a mould at a temperatureof 45° C. The notched Izod Impact of the injected materials wasevaluated according to ASTM D256 as shown in table 14. TABLE 14 PC/HIPSblends composition and Izod impact. Notched Izod Impact Diblock (0.125in) Blend. copolymer Lexan 121/Lexan 141/ Diblock lb-ft/in Example fromtable HIPS 40/Diblock Lexan Lexan HIPS copolymer ASTM number 1 or table5 copolymer 121 (g) 141 (g) 40 (g) (g) D256 54 none 47.50 20.5 32.00712.50 307.50 480.00 0.00 3.6 55 16 47.50 20.5 32.00 3 712.50 307.50480.00 45.00 4.6 56 2 47.50 20.5 32.00 3 712.50 307.50 480.00 45.00 6.1

The notched Izod impact properties of PC/HIPS blends is evaluated inexamples 54-56 using block copolymer 2 (see table 1), the randomcopolymer 16 (see table 5) and no compatibilizer. The results revealthat the block copolymer has a better performance than achieved usingthe random copolymer as a compatibilizer and of course better than theblend without a compatibilizer.

Examples 54-56 show how the block copolymers of the present inventioncan improve impact properties of polycarbonate by making it morecompatible with high-impact polystyrene.

Having described the invention above, various modifications of thetechniques, procedures, materials, and equipment will be apparent tothose skilled in the art. It is intended that all such variations withinthe scope and spirit of the invention be included within the scope ofthe appended claims or within the scope of claims subsequently made tothe invention.

1. A process for producing a block copolymer, comprising: a) reacting anacrylic monomer having functional groups and one or more vinyl monomersin the presence of a free radical initiator and a stable free radical ina first step to form a reaction product, wherein the reaction productincludes residual unreacted acrylic monomer; and b) reacting in a secondstep one or more vinyl monomers with the reaction product from the firststep to form a second block, wherein the second block incorporates theresidual unreacted acrylic monomer.
 2. The process according to claim 1,wherein the acrylic monomer is selected from the group consisting ofglycidyl methacrylate, acrylic acid, methacrylic acid, 2-hydroxyethylmethacrylate, maleic anhydride, 2-dimethylaminoethyl methacrylate and2-diethylaminoethyl methacrylate.
 3. The process according to claim 1,wherein the vinyl monomer in the first step is styrene.
 4. The processaccording to claim 1, wherein the vinyl monomers in the second step areselected from the group consisting of styrene, N-phenylmaleimide, methylmethacrylate and butyl acrylate.
 5. The process according to claim 1,wherein the reaction product includes at least 0.03 mole percentunreacted residual acrylic monomer.
 6. The process according to claim 1,wherein the stable free radical is a nitroxyl free radical.
 7. Theprocess according to claim 1, wherein the stable free radical is formedfrom an alkoxyamine.
 8. The process according to claim 1, wherein thestable free radical is a nitroxyl free radical having the structuralformula:

wherein R1 and R4 are independently selected from the group consistingof hydrogen, alkyl, aryl and heteroatom-substituted alkyl or aryl, andwherein R2 and R3 are independently selected from the group consistingof alkyl, aryl and heteroatom-substituted alkyl or aryl; and X1 and X2are independently selected from the group consisting of halogen, cyano,COOR11 (wherein R11 is alkyl or aryl), amido, S—C6H5, S—COCH3, —OCOC2H5,phosphonate, phosphate, carbonyl, aryl, alkenyl, alkyl or can be takentogether to form a ring structure with the nitrogen.
 9. The processaccording to claim 1, wherein the stable free radical is selected fromthe group consisting of 2,2,6,6-tetramethyl-1-piperidinyloxy,4-hydroxyl-2,2,6,6-tetramethyl-1-piperidinyloxy,4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxy, tert-butyl1-diethylphosphono-2,2-dimethylpropyl nitroxide, tert-butyl1-phenyl-2-methylpropyl nitroxide, and derivatives thereof.
 10. Theprocess according to claim 1, wherein the free radical initiator isselected from the group consisting of:2,2′-Azobis(2-Methylpropanenitrile), 2,2′-Azobis(2-Methylbutanenitrile),dibenzoyl peroxide (BPO), Tert-Amyl peroxy-2-ethylhexanoate, Ter-Butylperoxy-2-ethylhexanoate,2,5-Bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane and ter-Butylperoxydiethylacetate.
 11. The process according to claim 1, wherein themolar ratio of total monomer to initiator is in the range of about 50 toabout 12,000.
 12. The process according to claim 1, further comprisingadding additional initiator during the second step.
 13. The processaccording to claim 1, wherein the first step takes place in a stirredtank reactor until a conversion of about 14 to about 90% is obtained.14. The process according to claim 13, wherein the second step iscarried out in a second reactor without agitation until a conversion ofabout 90 to about 100% is obtained.
 15. The process according to claim14, wherein the second reactor is a slab mold reactor.
 16. The processaccording to claim 13, wherein the second step is carried out in asecond reactor with agitation until a conversion of about 60 to about100% is obtained.
 17. The process according to claim 16, wherein thesecond reactor is a kneader reactor.
 18. A process for making a blockcopolymer, comprising: a) reacting in a first step styrene and anacrylic monomer selected from the group consisting of glycidylmethacrylate, acrylic acid, 2-hydroxyethyl methacrylate, maleicanhydride and 2-diethylaminoethyl methacrylate in the presence of a freeradical initiator and a nitroxide-based stable free radical at atemperature ranging between about 80° C. and about 135° C. to aconversion ranging between about 14 to about 90 percent to form areaction product including a first block and residual monomer, whereinthe reaction product includes at least about 0.03 mole percent residualunreacted acrylic monomer; and b) reacting in a second step one or moremonomers selected from the group consisting of styrene,N-phenylmaleimide, methyl methacrylate and butyl acrylate with thereaction product from the first step to form a second block containingmonomer units of the acrylic monomer from the first step.
 19. A processfor producing a block copolymer, comprising: a) reacting an acrylicmonomer having functional groups and one or more vinyl monomers in thepresence of a free radical initiator, a stable free radical and asolvent to form a reaction product, wherein the reaction productincludes a first block and residual unreacted acrylic monomer; and b)reacting one or more vinyl monomers with the residual unreacted acrylicmonomer and the first block in the reaction product to form a secondblock that is bonded to the first block.
 20. The process according toclaim 19, wherein step (a) takes place in a stirred tank reactor until aconversion of about 14 to about 90% is obtained and step (b) is carriedout in a second reactor with or without agitation until a conversion ofabout 90 to about 100% is obtained.
 21. A process for producing a blockcopolymer, comprising: a) reacting an acrylic monomer having functionalgroups and one or more vinyl monomers in the presence of a free radicalinitiator and a stable free radical to form a reaction productcontaining a first block and residual unreacted acrylic monomer; and b)reacting one or more vinyl monomers with the reaction product in thepresence of a solvent to form the block copolymer, the block copolymercomprising a second block bound to the first block, wherein the secondblock has functional groups provided by the residual unreacted acrylicmonomer.
 22. The process according to claim 21, wherein the first steptakes place in a stirred tank reactor until a conversion of about 14 toabout 90% is obtained and the second step is carried out in a secondreactor with or without agitation until a conversion of about 90 toabout 100% is obtained.
 23. A block copolymer having a composition,comprising: a) a first block comprising monomeric units of afunctionalized acrylic monomer and monomeric units of a vinyl monomer;and b) a second block comprising monomeric units of one or more vinylmonomers and monomeric units of the functionalized acrylic monomer inthe first block.
 24. The block copolymer of claim 23, wherein thefunctionalized acrylic monomer in the block copolymer ranges betweenabout 0.5 and about 70 weight percent.
 25. The block copolymer of claim23, wherein the residual monomers from the first block contain at least1% w/w of the functionalized acrylic monomer.
 26. The block copolymer ofclaim 23, wherein the acrylic monomer is selected from the groupconsisting of glycidyl methacrylate, acrylic acid, methacrylic acid,2-hydroxyethyl methacrylate, maleic anhydride, 2-dimethylaminoethyl,methacrylate and 2-diethylaminoethyl methacrylate.
 27. The blockcopolymer of claim 23, wherein the vinyl monomers of the first block areselected from the group consisting of styrene, substituted styrenes,substituted acrylates and substituted methacrylates.
 28. The blockcopolymer of claim 23, wherein vinyl monomer in the second block isselected from the group consisting of styrene, substituted styrenes,acrylonitrile, N-aromatic substituted maleimides, N-alkyl substitutedmaleimides, maleic anhydride, acrylic acid, methyl methacrylate, alkylsubstituted acrylates, aryl substituted acrylates, alkyl substitutedmethacrylates, aryl substituted methacrylates and 2-hydroxyethylmethacrylate.
 29. A thermoplastic polymer composition, comprising: (a)1-98 wt % of a first thermoplastic having functional groups selectedfrom the group consisting of amino, amide, imide, carboxyl, carbonyl,carbonate ester, anhydride, epoxy, sulfo, sulfonyl, sulfinyl,sulfhydryl, cyano and hydroxyl; (b) 0.01-25 wt % of the block copolymerof claim 23, wherein the block copolymer contains a functional groupthat is capable of reacting with a functional group on thethermoplastic; and (c) 1-98 wt % of a second thermoplastic polymer,wherein the second thermoplastic polymer is miscible with or compatiblewith the second block of the block copolymer of claim
 23. 30. Thecomposition of claim 29, wherein the block copolymer is made by theprocess of claim
 1. 31. The composition of claim 29, wherein the blockcopolymer is made by the process of claim
 18. 32. The thermoplasticpolymer of claim 29, wherein the number average molecular weight of theblock copolymer ranges between about 5,000 and about 200,000.
 33. Thecomposition according to claim 29, wherein the first thermoplasticpolymer, which has functional groups, is selected from the groupconsisting of aliphatic or aromatic polycarbonates, polyesters,polyamides, polyphenylene ether, polyolefins having epoxy, anhydride oracid functionalities, polysulfones, polyurethanes and mixtures thereof.34. The composition according to claim 29, wherein the secondthermoplastic polymer, which is miscible with or compatible with thesecond block of the block copolymer, is selected from the groupconsisting of polystyrene, poly substitued styrenes, styrenic randomcopolymers, styrenic block copolymers, high impact polystyrene,hydrogenated block copolymer of styrene and a diene monomer,polyphenylene ether, polyacrylates, polymethacrylates, acrylate randomcopolymers, acrylate block copolymers, methacrylate random copolymers,methacryalte block copolymers, polyolefins, polyurethanes, polyvinylchloride, polyvinylidiene chloride, polyvinyl fluoride, polyvinylidienefluoride styrene acrylic copolymers, copolymers containing units ofstyrene and acrylonitrile, copolymers containing units of styreneacrylonitrile and butadiene, copolymers containing units of styreneacrylonitrile and n-butyl acrylate, copolymers containing units ofstyrene acrylonitrile, butadiene and n-butyl acrylate, and mixturesthereof.
 35. The composition according to claim 29, further comprisingone or more polymer additives selected from the group consisting ofstabilizers, antioxidants, flow aids, flame retardants, impactmodifiers, nucleating agents, pigments and fillers.
 36. A tie layermaterial for adhesively bonding plastic film layers one to another toform a laminate structure thereof, said tie layer material comprising ablock copolymer made by the process of claim
 1. 37. A tie layer materialfor adhesively bonding plastic film layers one to another to form alaminate structure thereof, said tie layer material comprising a blockcopolymer having a composition according to claim
 23. 38. A method formaking a laminate, comprising extruding two plastic layers and a tielayer, wherein the tie layer is located between the two plastic layersand has a composition according to claim 23.